SAWE Technical Papers

@inproceedings{3593,

title = {3593. Trade Study of System Level Ranked Radiation Protection Concepts for Deep Space Exploration},

author = {Jeffrey Cerro},

url = {https://www.sawe.org/product/paper-3593},

year  = {2013},

date = {2013-05-01},

booktitle = {72nd Annual Conference, St. Louis, Missouri},

pages = {18},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Saint Louis, Missouri},

abstract = {A strategic focus area for NASA is to pursue the development of technologies which support exploration in space beyond the current inhabited region of low earth orbit. An unresolved issue for crewed deep space exploration involves limiting crew radiation exposure to below acceptable levels, considering both solar particle events and galactic cosmic ray contributions to dosage. Galactic cosmic ray mitigation is not addressed in this paper, but by addressing credible, easily implemented, and mass efficient solutions for the possibility of solar particle events, additional margin is provided that can be used for cosmic ray dose accumulation. As a result, NASA's Advanced Engineering Systems project office initiated this Radiation Storm Shelter design activity. This paper reports on the first year results of an expected 3 year Storm Shelter study effort which will mature concepts and operational scenarios that protect exploration astronauts from solar particle radiation events. Large trade space definition, candidate concept ranking, and a planned demonstration comprised the majority of FY12 activities. A system key performance parameter is minimization of the required increase in mass needed to provide a safe environment. Total system mass along with operational assessments and other defined protection system metrics provide the guiding metrics to proceed with concept developments. After a downselect to four primary methods, the concepts were analyzed for dosage severity and the amount of shielding mass necessary to bring dosage to acceptable values. Besides analytical assessments, subscale models of several concepts and one full scale concept demonstrator were created. FY12 work terminated with a plan to demonstrate test articles of two selected approaches. The process of arriving at these selections and their current envisioned implementation are presented in this paper.},

keywords = {18. Weight Engineering - Spacecraft Design, 19. Weight Engineering - Spacecraft Estimation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3569,

title = {3569. Revisiting Seawater Density and its Impact on Submarine Design},

author = {David Tellet},

url = {https://www.sawe.org/product/paper-3569},

year  = {2013},

date = {2013-05-01},

booktitle = {72nd Annual Conference, St. Louis, Missouri},

pages = {88},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Saint Louis, Missouri},

abstract = {This paper presents an analysis of seawater density data and relates the findings to submarine design impacts. Oceanographic temperature, depth, and salinity data from all the Earth's oceans and seas were analyzed to test the hypothesis that the standard heavy density value used by the US Navy could be reduced for certain submarine designs. The data support the hypothesis. Design impacts of reducing water density requirement are noted. The paper includes a summary table of all the data and detailed summary sheets for each of the 100 separate datasets used in the analysis.},

note = {Mike Hackney Best Paper Award},

keywords = {Marine, Mike Hackney Best Paper Award},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3565,

title = {3565. Weight Aspects Of Glare Fiber Metal Laminates},

author = {Cees G. Hengel},

url = {https://www.sawe.org/product/paper-3565},

year  = {2013},

date = {2013-05-01},

booktitle = {72nd Annual Conference, St. Louis, Missouri},

pages = {24},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Saint Louis, Missouri},

abstract = {Fiber Metal Laminates (FML's) are a class of hybrid materials consisting of thin metal layers, bonded together by layers of adhesive reinforced with high-strength fibers. FML's have a metal-like appearance and several metal-like properties including plasticity Today, after its selection as skin material on the fuselage of the A380 in 2000, Glare FML is well underway to become an established technology in the aerospace industry, combining low weight with high durability and damage tolerance at competitive costs. 

This paper presents a basic introduction to GLARE FML's and the associated technology. It identifies four application categories where Glare FML's can be beneficially applied: stiffened panels as part of the primary load carrying structure, local reinforcements, secondary structures, and special structures with integrated functionalities (or 'smart structures'). These categories are illustrated with specific products. The reasons why Glare was selected for these products is illustrated by showing the potential of the Glare technology for each of the three product defining disciplines of materials, manufacturing and design. 

Weight aspects of Glare FML's are discussed in the context of the design process as they could present themselves to weight engineers, and some cost aspects are discussed. Weight savings of 10% to over 30% are shown, depending on the specifics of the situation. 

Based on the foregoing, it is concluded that Glare FML is a mature technology that enables the creation of light weight aircraft structures with high durability and high damage tolerance, at reasonable cost and low risk. 

Based on current design and production experience, and considering the broad development potential, it seems reasonable to expect that Glare FML's will be strong candidates for future aircraft structures.},

keywords = {27. Weight Reduction - Materials},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3592,

title = {3592. A Background in Offshore Floating Production Unit Weight Control Nomenclature and a Proposal for Future Development},

author = {Radoslaw Zawadzki},

url = {https://www.sawe.org/product/paper-3592},

year  = {2012},

date = {2012-05-01},

booktitle = {71st Annual Conference, Bad Gögging, Germany},

pages = {9},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Bad Gögging, Germany},

abstract = {In estimating and managing weight growth during concept, design and fabrication phases for offshore energy floating production platforms and vessels, two similar but different methodologies for representing weight nomenclature have arisen thus leading to confusion and turmoil within the weight control discipline. This paper delves into the background and origins of these weight control methodologies and seeks to open the discussion on the differing nomenclatures found within the weight control function. This will be done by giving some examples of weight control terminology with multiple definitions and proposing a new concept of weight nomenclature based on the stages and states of weight development.},

keywords = {17. Weight Engineering - Procedures, 35. Weight Engineering - Offshore, Marine},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3589,

title = {3589. An Integrated And Rapid Fem-Based Weight Derivation Approach To Weight Estimation},

author = {Jorge Antonio Bes-Torres and Robby Rudsianto and Edward Kay},

url = {https://www.sawe.org/product/paper-3589},

year  = {2012},

date = {2012-05-01},

booktitle = {71st Annual Conference, Bad Gögging, Germany},

pages = {23},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Bad Gögging, Germany},

abstract = {Driven by the industrial demand to shorten a typical aircraft design cycle, a lot of research effort has been invested by Airbus to develop an integrated and rapid multi-disciplinary approach to aircraft design and optimisation. Given a specific aircraft mission and high level a/c requirements, the primary objective is to be capable of analysing the entire aircraft design space within a short period of time by rapidly assessing multiple concepts and converging on the most optimum a/c architecture.. Traditional design process focussed generally in structural optimisation to achieve structural design that deliver the lightest FEM weights and neglecting the true manufacturable weights. This paper aims to present to readers a rapid and integrated FEM based and weight derivation approach to weight estimation of aircraft components. The key strength of this approach is that it takes into consideration structural optimisation and manufacturing constraints to derive true manufacturing weights and allowing new and unconventional aircraft concepts to be studied.},

keywords = {11. Weight Engineering - Aircraft Estimation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3586,

title = {3586. SWAT: Systematic Weight Analysis and Reduction Method},

author = {Kossow Matthias and Konstantin Graf and Torben Kabbe},

url = {https://www.sawe.org/product/paper-3586},

year  = {2012},

date = {2012-05-01},

booktitle = {71st Annual Conference, Bad Gögging, Germany},

pages = {24},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Bad Gögging, Germany},

abstract = {The systematic reduction of weight has become an important key factor for a variety of industrial applications. The reduction of weight - typically - has a positive impact on less energy consumption, range increase, payload enlargement, preserving resources, and saving costs. Assuming that all easy and obvious weight saving ideas have already been implemented when people start to think about applying specific weight saving methods creates two major statements: 

- To find new weight saving ideas a new way of thinking is mandatory. Therefore the involved people have to leave their so called 'comfort zone' and open their minds towards novel and uncommon ideas. 

- To find new weight saving ideas people have to accept the related risks as challenges that have to be solved to gain flexibility instead of allowing the perception of risks to 'kill' risky weight saving ideas. 

The SWAT-Method (SWAT stands for Systematic Weight Analysis and Reduction MeThod) determines potential of weight saving ideas by methodical functional system analysis and guided creativity. In addition it provides a clear and transparent view on the way forward for the deployment of ideas including risks: 

'SWAT is a formal systematic approach designed to develop and support your creativity.' 

and 

'SWAT identifies existing hidden flexibility that can be used for weight saving concepts.'},

keywords = {17. Weight Engineering - Procedures},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3585,

title = {3585. Graphene based Polymer Composites: Prospects of Application in design of Light Weight Aerospace Structural Components},

author = {Bangwei Zhang and Anwer A. Zaidi and Ramazan Asmatulu},

url = {https://www.sawe.org/product/paper-3585},

year  = {2012},

date = {2012-05-01},

booktitle = {71st Annual Conference, Bad Gögging, Germany},

pages = {17},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Bad Gögging, Germany},

abstract = {The use of new and exotic material, graphene, is explored in tailoring and designing composites to create aircraft structural parts. The synthesis and engineering of graphene is still in infancy but the future potential is enormous. Some initial tests and subsequent validation results for graphene is described to establish a baseline for its future use as structural parts, as a part of composite material system in aerospace Industry. Initial results of using graphene either as a strengthening ply with polymer matrix type laminate or as a fiber in traditional composite system, shows enormous potential. This is the key aspect researchers are relying on.},

keywords = {17. Weight Engineering - Procedures},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3584,

title = {3584. Weight Optimization of Aircraft Structures with Durability and Damage Tolerant Constraints},

author = {Anwer A. Zaidi},

url = {https://www.sawe.org/product/paper-3584},

year  = {2012},

date = {2012-05-01},

booktitle = {71st Annual Conference, Bad Gögging, Germany},

pages = {19},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Bad Gögging, Germany},

abstract = {Aircraft structural weight optimization is considered with Durability and Damage tolerant constraints. Nature of solution space for investigating the durability and damage tolerance of minimum weight structure is discussed. Altair's OptiStructfinite element driven solver of Hyperworkssuite is used to provide a sound ground up optimization in several stages. A generic aircraft structural component is investigated as a proof of the concept which provides weight saving methodology in the initial conceptual phase of design by rigorous applications of optimization tools.},

keywords = {17. Weight Engineering - Procedures},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3583,

title = {3583. Report Format For Weight Control Of Offshore Structures},

author = {Stein Bjòrhovde},

url = {https://www.sawe.org/product/paper-3583},

year  = {2012},

date = {2012-05-01},

booktitle = {71st Annual Conference, Bad Gögging, Germany},

pages = {35},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Bad Gögging, Germany},

abstract = {The purpose of this paper is to suggest standard layouts for printouts to be included in the weight report for engineering and construction of offshore structures. The proposals are based on a systematic review of weight reports for existing oil platforms built for the North Sea and Gulf of Mexico during the last 10 year. The content of these weight reports are systemized according to the ISO standard for weight control, as well as the Statoil requirement for weight control. 

Requirements for weight control of offshore structures are described in the ISO standard 19901-5 'Petroleum and natural gas industries - Specific requirements for offshore structures - Part 5: Weight control during engineering and construction'. This document includes definitions, weight control classes, weight- and load budgets, weight reporting, requirements for suppliers, requirements for weighing in addition to various appendixes. In this paper we will focus on chapter 6.3 'Requirements to the weight report'. The content of existing weight reports are systemized and mapped to the defined chapters (printouts/tables) that are required according to the ISO standard. 

The Norwegian energy company Statoil has a technical requirement for weight control titled 'TR2352 Weight control requirements for topside and substructures'. This document specifies among others which data fields the weight database should include as a minimum. One of the results of this paper is an overview of which data fields are included in the various weight report chapters required by the ISO standard. 

This paper can serve as a specification of the data fields and printouts that should be included in a weight control system for offshore structures to fulfill the requirements of the ISO-19901-5. The layouts of the printouts are in focus. In this paper it is also discussed whether it's realistic to design a weight control system that automatically or semi-automatically produces the weight reports. 

Stein Bjòrhovde is one of the founders and head of development of BAS Engineering. Mr. Bjòrhovde has a Master of Science Degree in Ship Design, and has been developing the weight engineering software ShipWeight since 1993. He has also been involved in development of other weight control software, in addition to being a consultant doing weight estimation and monitoring in the offshore industry. He has more than 15 years' experience in weight estimation of new ship designs for several Norwegian and international ship designers and yards.},

keywords = {17. Weight Engineering - Procedures, 35. Weight Engineering - Offshore},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3579,

title = {3579. An Empirical Aero Gas Turbine Preliminary Weight Estimation Method Based On Artificial Neural Networks},

author = {P. Lolis and B. Arumugam Shanmugasundaram and V. Sethi and P. Pilidis},

url = {https://www.sawe.org/product/paper-3579},

year  = {2012},

date = {2012-05-01},

booktitle = {71st Annual Conference, Bad Gögging, Germany},

pages = {12},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Bad Gögging, Germany},

abstract = {During the last years the number of parameters involved in the design and selection of an aero engine has greatly increased, making the decision for the most suitable aircraft engine at the preliminary design stage a challenging task. To cope with these requirements multi-disciplinary parametric tools, that perform Techno-economic and Environmental Risk Analysis (TERA) and trade-off studies have been introduced. These tools integrate several packages that model different aspects of the engine, aircraft and mission at the preliminary design stage. One of those is the preliminary weight estimation module, necessary for the aircraft performance, but also for the engine optimisation studies. 

Existing aero gas turbine preliminary weight estimation methods that are publicly available either fail to achieve the necessary accuracy or are complex and time consuming. Moreover, these methods are based on engine databases that are more than 30 years old, rendering them outdated and untrustworthy for recent engines. Therefore, there is a need for a new, more accurate, simple and fast method. 

The ability of empirical methods to better capture aspects that cannot be modelled easily, combined with the availability of data for the whole aero engine weight, led to the development of a new method based on an aero gas turbine database. Take-off thrust, overall pressure ratio, by-pass ratio and year of entry into service are the four key variables influencing the engine weight that were selected for the present study. To analyse the available data Artificial Neural Networks (ANNs) were selected as the most suitable tool, due to their ability to model effectively complex patterns and relations. 

This paper includes an analysis of several possible feedforward backpropagation ANN configurations and their comparison based on accuracy, simplicity and calculation time with the two hidden layer emerging as the most suitable configuration. However, the error achieved is higher than the indicated limit of ~10% for engine optimisation studies. Therefore several improvements are suggested for expansion of the database and alternative configurations that will help reduce the calculated error.},

keywords = {11. Weight Engineering - Aircraft Estimation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3577,

title = {3577. Method For The Reduction Of Analytical Weight Estimation Models For The Use In Early Project Phases},

author = {Daniel Lindner},

url = {https://www.sawe.org/product/paper-3577},

year  = {2012},

date = {2012-05-01},

booktitle = {71st Annual Conference, Bad Gögging, Germany},

pages = {36},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Bad Gögging, Germany},

abstract = {Weight estimation is a very important topic during all phases of aircraft development. It is indispensible for the estimation of loads and aircraft inertias to have a funded estimation of the weight of the aircraft's components and the position of their center of gravity. A realistic estimation can be quite complicated especially during very early stages of aircraft development. Additionally, due to the increasing level of available information on the new design, it is necessary to change the method and tool for the estimation during the development process. However, this change of methodology cannot inflict major changes on the estimated weight for a specific component. Neither can it change the sensitivities of the component's weight to the main sizing parameters. It is important to guarantee the continuity of the estimation and the sensitivities over the whole tool chain. 

This paper shows a top down approach to the development of weight estimation methods for very early project phases. In order to being able to guarantee the continuity of the estimation, the model for early phases is developed as a reduced model of an existing high level analytical estimation tool. Through statistical analysis the main driving parameters of the top level method are determined. A reduced model is being developed based on those parameters and the sensitivities of the top model with respect to those parameters. This way both, the continuity of the estimated weight and the continuity of the major sensitivities between the reduced and the top level model, can be guaranteed. The methodology is described theoretically and applied to the estimation of the pylon primary structure weight. This component is very important for trade off studies in early phases with respect to the engine position. Therefore it is necessary to have good sensitivities for this estimation method. For the model reduction process itself a mathematical and a physical approach have been performed and the results analyzed and compared. Finally, the paper gives methods for checking the correct modeling of the major sensitivities compared to the top level tool.},

keywords = {11. Weight Engineering - Aircraft Estimation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3576,

title = {3576. Automation Methods Of Aircraft Weight Activities},

author = {O Isikdogan and T Kiper and E Unay and D. Gurak},

url = {https://www.sawe.org/product/paper-3576},

year  = {2012},

date = {2012-05-01},

booktitle = {71st Annual Conference, Bad Gögging, Germany},

pages = {12},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Bad Gögging, Germany},

abstract = {This paper presents the optimization and automation efforts for aircraft weight activities in aircraft design projects. Those weight activities involve monitoring the aircraft total weight and inertia, evaluation of weight breakdown and calculation of mass and inertia distribution. The results are then submitted to project management, flight mechanics, structural analyses and design groups. The methods and tools developed for this study provide less time-consuming process and more accurate results. The mass and inertia properties of the aircraft are subject to change progressively during an aircraft design process. The challenge is to monitor those changes and report their effects instantly. An integrated system is designed to make all those weight activities to be automatically performed and controlled. The system works simultaneously with Computer Aided Design (CAD) software and provides real time monitoring of weight properties and weight breakdown of aircraft. In addition, this system helps the weight data to be more accessible and updated. Also, mass and inertia distribution of aircraft is evaluated in this integrated system as the mass model, consisting of lumped masses, required from related analysis groups. The most common method for this mass distribution calculation is slicing functions of CAD software. However, the methods developed for the weight activities help overcome the inefficiencies of solely depending on CAD software for large assemblies consisting of thousands of detailed parts, sub-assemblies, equipments, harness, systems etc. These tools are designed to be used in all phases of the aircraft design process, from conceptual to detailed design. In conclusion, the integrated system developed for the automation of weight activities is mentioned and compared to common methods used in industry. The advantages and impact of those new methods and tools to aircraft design are presented.},

keywords = {12. Weight Engineering - Computer Applications},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3571,

title = {3571. An Advanced Quasi-Analytical Weight Estimation Method for Airplane Lifting Surfaces},

author = {Ali Elham and Gianfranco La Rocca and Michel J. L. Tooren},

url = {https://www.sawe.org/product/paper-3571},

year  = {2012},

date = {2012-05-01},

booktitle = {71st Annual Conference, Bad Gögging, Germany},

pages = {19},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Bad Gögging, Germany},

abstract = {This paper describes a novel weight prediction method for aircraft lifting surfaces, which is able to combine the typical accuracy of finite element (FE) based weight estimation methods, with the computational speed of the classical semi empirical (class II) methods used in conceptual design. 

In the proposed method the use of semi empirical equations is limited to the estimation of the secondary weights of wing and tailplanes. The weight prediction of the primary structure is achieved by means of an advanced analytical method, which makes use of the actual geometry of aerodynamic surfaces and structural layout, and the computed lift forces distribution. In particular, a set of mathematical equations has been derived to relate the required structural properties of the wing box to the specific shape of the used airfoils. These equations allow modelling the skin, the spar caps and the stringers of the upper and lower side of a given wing box into two equivalent flat panels, and then calculate their 'effective distance'. This distance is indeed the factor that allows accounting for the effect of the given airfoil shape on the stress distribution in the panels, and enable a more accurate panel weight estimation than other methods proposed in literature. 

A realistic estimation of the spanwise lift distribution is another key factor to achieve accurate weight predictions. To this purpose, a commercial Vortex Lattice Method tool has been employed top derive the aerodynamic loads on the given lifting surface. The load cases are defined according to airworthiness regulations. The load relief effects provided by fuel and engine installation, as well as by the weight of the wing structure, are taken into account. 

The total weight of the given lifting surface is computed by adding the analytically calculated weight of upper and lower panels, spars and ribs, to the weight of the secondary structure (e.g., movables and fixed leading and trailing edge) and to the so called non-optimum weight group, which accounts for joints, cut-outs, attachments, etc. The last two contributions are estimated by means of semi empirical relations. 

The proposed lifting surface weight prediction method has been validated using data of various airplanes of different size, category and manufacturer. The computational time is dramatically lower than any finite element based sizing tool, while the achieved level of accuracy is comparable or even higher. Each weight prediction takes about 10 second on a standard PC. The average error on lifting surface total weight is less than 2%. Besides, the achieved combination of speed, accuracy and high level of design sensitivity (designer can assess the effect on weight of such parameters as airfoil shape, number, position and orientation of structural items, etc.) make the proposed tool suitable for multidisciplinary design optimization studies.},

keywords = {10. Weight Engineering - Aircraft Design},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3566,

title = {3566. Multidisciplinary Analysis and Optimization in the Conceptual Aircraft Design Phase to Support Early Mass Predictions},

author = {Johannes Schweiger and Moritz Büsing and Jens Feger},

url = {https://www.sawe.org/product/paper-3566},

year  = {2012},

date = {2012-05-01},

booktitle = {71st Annual Conference, Bad Gögging, Germany},

pages = {19},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Bad Gögging, Germany},

abstract = {A new approach in conceptual aircraft design at Cassidian is presented which supports the initial assessment of mass data for a new configuration. It is based on the fast creation of a multidisciplinary analytical model for the description of the complete vehicle and the application of mathematical optimization methods to determine the mass of its structural components, sub- ject to external loading conditions and requirements for the structural stiffness to meet the es- sential performance constraints. 

In the first place, this process serves as a tool that helps to find the optimum overall design for the top level requirements like range and payload by a direct coupling of the structural lay out with the vehicle's conceptual design topology and sizing process. 

Mass data from this process help to confirm and adjust the classic mass estimation process which is based on statistic and semi-empirical data for the individual components of the vehicle but also for the global mass properties like center of gravity location and mass moments of in- ertia, which are also important during the initial sizing process. 

In addition, the method help to find optimum solutions for the integration of heavy equipment by directly including the impacts from the attachment loads of these equipment items to the structure, as well as the related interactions with the vehicle's flutter stability. 

The basic analysis and optimization tool for this process is the Cassidian in-house program LAGRANGE. Its development started 30 years ago, based on the needs to assess and include all relevant design requirements for the stiffness and strength of an aircraft structure into the design process from the very beginning, and at the same time explore and exploit the new pos- sibilities of 'tailoring' the strength and stiffness properties of carbon composites. 

Whereas initial structural analysis and optimization application started by setting up rather sim- ple structural analysis models from 'scratch', recent years showed a trend towards first creat- ing computer aided design models and then derive the analysis models from these already rather complex designs. The approach which is described in this paper is different from similar efforts because it starts with the creation of the analytical models by simple input data only. Its results can then be used to create or update the design model. The time to set up the complete model for a new configuration is less than one day, and it takes only minutes or few hours to modify the model for a different geometry, different requirements, or different options for the optimization process. 

Especially for new configurations, where no or only very limited statistical data exist from com- parable projects, this new approach is very useful to support the generation and tracking of mass data, and it helps to minimize these masses by using analytical sensitivities for the es- sential design variables as functions from a set of complex design requirements from different disciplines. 

An example is presented for a generic medium-altitude-long endurance (MALE) UAV.},

keywords = {11. Weight Engineering - Aircraft Estimation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3564,

title = {3564. Multi-Fidelity Wing Mass Estimations Based On A Central Model Approach},

author = {Daniel Böhnke and Felix Dorbath and Björn Nagel and Volker Gollnick},

url = {https://www.sawe.org/product/paper-3564},

year  = {2012},

date = {2012-05-01},

booktitle = {71st Annual Conference, Bad Gögging, Germany},

pages = {18},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Bad Gögging, Germany},

abstract = {Although computational power is constantly increasing and Moore's Law is still not falsified, computational cost remains an essential barrier in aircraft design especially when a high number of design evaluations is necessary. This is especially true at the conceptual design stage of aircraft. While determining the characteristics of a new configuration the number of iterations and the low level of detail in the available data limit the analyses to simple empiric methods. 

Nevertheless, at a later point in the design it is necessary to determine parameters like the wing mass with higher-fidelity analysis modules. Especially when assessing configurations that lie outside of the well-known design space of conceptual design, empiric methods become unreliable. Examples to name include high aspect ratio and forward-swept wings. 

In this study a combination of an empiric method, a beam model and vortex lattice model for aerodynamic loads is introduced. While multi-fidelity approaches are already well known, this study focuses on the fact that all analysis modules derive their data from the same data model. Working on a central data model decreases the number of required interfaces and guarantees that all models relate to the same input data, i.e. a compliant geometry definition. 

This paper includes a design chain starting from the conceptual design tool VAMPzero as initiator for the more advanced models PESTwing and TRIMvl. Using the PESTwing tool a large design space will be explored. An equation for determination of the wing mass based on a physical model is then derived and compared to existing methods in conceptual design.},

keywords = {11. Weight Engineering - Aircraft Estimation, 23. Weight Engineering - Structural Estimation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3562,

title = {3562. Parametric Estimation Of Anchor Handling / Towing Winches},

author = {Stein Bjòrhovde and Runar Aasen},

url = {https://www.sawe.org/product/paper-3562},

year  = {2012},

date = {2012-05-01},

booktitle = {71st Annual Conference, Bad Gögging, Germany},

pages = {13},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Bad Gögging, Germany},

abstract = {Anchor Handling Tug vessels (AHT) are ships built to handle anchors for oil rigs, in addition to towing the platforms into position and in some cases operate as Emergency Rescue and Recovery Vessel (ERRV). Compared to ordinary offshore supply vessels, AHTs are characterized by large winches for towing and anchor handling, open stern for landing of anchors and a large bollard pull. 

The winch packages for anchor handling tug vessels are large and heavy constructions with weight that varies from 150 to 900 tonnes and may represent as much as 15% of the lightship weight for the vessel. In addition to significant weight, it also influences a lot on the vertical center of gravity (VCG) og thereby the stability of the ship. Also the longitudinal center of gravity (LCG) is significantly influenced by the layout and positioning of this equipment. 

Experience shows that it might be difficult to identify reliable weight and center of gravity (CoG) for this special made equipment from fabricators and suppliers in an early design phase. Based on this we want to study which parameters are relevant for estimating weight and CoG for anchor handling / towing winches, and how these parameters can be combined in mathematical formulas that can be used in regression based estimation. 

The advantage of using regression is among others the quantification of uncertainty (standard deviation) related to each specific estimation method and thereby the possibility to decide which methods that are the most precise, and to evaluate whether parametric estimation can be used at all. An evaluation of the uncertainty requirements will be performed as well. 

Stein Bjòrhovde is one of the founders and head of development of BAS Engineering. Mr. Bjòrhovde has a Master of Science Degree in Ship Design, and has been developing the weight engineering software ShipWeight since 1993. He has also been involved in development of other weight control software, in addition to being a consultant doing weight estimation and monitoring in the offshore industry. He has more than 15 years experience in weight estimation of new ship designs for several Norwegian and international ship designers and yards. 

Runar Aasen is one of the founders and technical sales manager of BAS Engineering, a SAWE corporate member. Mr. Aasen has a Master of Science Degree in Ship Design, has been extensively involved in the development of weight engineering software and user support for the last fourteen years, and became a SAWE Fellow Member in 2006. Since 1996, BAS Engineering has provided ship designers and builders around the world with naval architecture and mass properties support. BAS Engineering's ShipWeight software entered the US market for the first time in 1998 and has since been adapted by major US shipyards and designers.},

keywords = {25. Weight Engineering - System Estimation, 35. Weight Engineering - Offshore},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3559,

title = {3559. Fuel Mass Properties Calculation with CATIA V5},

author = {Ralf Funk},

url = {https://www.sawe.org/product/paper-3559},

year  = {2012},

date = {2012-05-01},

booktitle = {71st Annual Conference, Bad Gögging, Germany},

pages = {21},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Bad Gögging, Germany},

abstract = {Complex aircraft tank geometries due to challenging requirements are designed nowadays using CAD allowing analysis in a concise and cheap way. For fuel mass properties calculation inside CATIA V5 a corresponding feature has to be provided via fuel macro. 

This programme can be used in the various design and development phases of an aircraft. Hence this tool is qualified for analysis of simple cuboids in the Pre-Draft as well as positioned and optimised tank geometries with integrated pumps or pipes in the Pre-Design-Phase, Product-Design-Phase or In-Service-Phase. 

Fuel mass properties are essential for aircraft moments of inertia (MOI) determination, flight performance (Flight Control System) and mission performance evaluation. 

Processing with CATIA V5 is possible for CAD-solids, which are designed in the CATIA V4/ V5 environment or having a compatible file format. Before starting the analysis it is necessary to install the basic settings and to prepare the files with a powercopy providing the CAD-model with various parameters and geometry, thus the user of this programme requires a basic knowledge of CATIA V5. 

This paper gives an overview to run the fuel macro for individual tanks or tank groups for various configured fuel rundown sequences. The simplification of internal tank geometry is compensated by a feature of the tool which provides fuel density variation. Further input parameters are the flight attitude with individual air space and unusable fuel. 

The Log-File contains apart from fuel mass properties of tank geometries the input parameters and more detailed information for interpretation of results.},

keywords = {11. Weight Engineering - Aircraft Estimation, 12. Weight Engineering - Computer Applications},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3554,

title = {3554. Mass Analysis - An Important Discipline of the 'Luftfahrttechnisches Handbuch' (Aeronautical Engineering Handbook)},

author = {Stephan G. Scheidler},

url = {https://www.sawe.org/product/paper-3554},

year  = {2012},

date = {2012-05-01},

booktitle = {71st Annual Conference, Bad Gögging, Germany},

pages = {15},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Bad Gögging, Germany},

abstract = {The 'Luftfahrttechnisches Handbuch' (LTH) is an Aeronautical Engineering Handbook, which contains a number of disciplines such as Aerodynamics (AD), Propulsion Technology (AT), Loads (BM), Composite Design Criteria (FL), Flight Test Engineering (FV), Structural Analysis (HSB), Mass Analysis (MA), and Systems Engineering (SE) - please note that the abbreviation characters are according to the German titles. The discipline Mass Analysis covers various chapters such as General Basics, Methodologies, Mass Control, and Total Mass under Varying Load Conditions, Mass of Structures, Mass of Propulsion Systems, Mass of Equipment, and Payload etc. 

The LTH handbook as presented here is a tool for engineers, students, and other interested experts in industry, institutions, universities and authorities to specify, design, develop, verify, qualify, certify and analyse entire aeronautical vehicles, and their systems, engines and equipment. The LTH is aimed at standardising certain procedures and methods, and collects the knowledge of its members centrally. A search function is available for data retrieval. Rationalisation is provided via the generic acceptance of many of the shown verification processes by various civil and military authorities. This allows for optimised and accelerated development of aeronautical systems and provides authorities, OEM's and suppliers with a standardised basis for development and certification. 

In addition, the LTH is not only a compendium - it is also a community of the respective system specialists or, in other words, a network between its members and partners. All papers contained in the LTH have been reviewed and approved by the respective discipline's specialists committee, which consists of members from industry, institutions, universities and authorities. All specialists committees allow also other interested national or international parties to attend meetings in a guest status, or to join the committee as a regular member, if jointly accepted by the committee. This allows for a continuous process of improving existing and collecting new knowledge to optimise the LTH. Whilst the LTH originally started off in German language only, an approach has now been launched to internationalise the LTH by conversion into the English language, which has already partially been accomplished with a focus on data and software for actual technical problems and questions in aeronautical engineering. Further details of the LTH are provided on the public section of the website: www.lth-online.de.},

keywords = {30. Miscellaneous},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3553,

title = {3553. Vehicle Inertia Measurement Machine (VIMM)},

author = {Daniel Wegener},

url = {https://www.sawe.org/product/paper-3553},

year  = {2012},

date = {2012-05-01},

booktitle = {71st Annual Conference, Bad Gögging, Germany},

pages = {11},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Bad Gögging, Germany},

abstract = {For the design of modern vehicles the knowledge of mass and moments of inertia is of great importance in terms of their vibration behaviour. Next to the type of incitation the inertia tensor (mass, position of centre of gravity, moments of inertia and products of inertia) is crucial for the translational and rotational vibration behaviour. 

In vehicle development simulation models are used increasingly to investigate the dynamic behaviour of motor vehicles. These models are indispensable in the development of modern vehicle controls (e.g. ESP, antilock brake system). The knowledge of the inertia parameters of a vehicle is an important requirement to be able to represent a realistic driving behaviour in the simulation model. 

Moreover, the inertia parameters of a vehicle are used for the evaluation of the rollover stability. The National Highway Traffic Safety Administration (NHTSA) awards 'stars' for classification of the roll over stability. 

Because of this, the identification of parameters by measurement is of great importance and increasingly moves in the centre of interest of producers and public institutions. 

Traditional test methods for the determination of vehicle parameters split the investigation in several processing steps, whereas for each inertia parameter a separate test is required. This leads to disadvantages with regard to the reproducibility of the measurement and the required time. Newer test benches use an active movement mechanism as well as a sensor system to detect the movement and the forces and moments, which affects the body. Therefore the technical burden on the active movement mechanism and the sensory is high. 

A representative of those test benches is the VIMM (Vehicle Inertia Measuring Machine), which has been developed at ika. It is able to measure all inertia parameters and consists of a spherically seated platform, which can be moved by servo-hydraulic actuators around the three axes. The vehicle, whose inertia parameters are to be measured, is adapted on the platform. During the measurement the angular positions and the forces affecting the platform are measured. Afterwards the inertia parameters are calculated with these values.},

keywords = {03. Center Of Gravity},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3547,

title = {3547. Implementation of a Tool Chain for Extended Physics-Based Wing Mass Estimation in Early Design Stages},

author = {Felix Dorbath and Björn Nagel and Volker Gollnick},

url = {https://www.sawe.org/product/paper-3547},

year  = {2012},

date = {2012-05-01},

booktitle = {71st Annual Conference, Bad Gögging, Germany},

pages = {21},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Bad Gögging, Germany},

abstract = {The state-of-the-art methods in preliminary wing design are using models employing physics-based methods for primary structures while using empirical correlations for secondary structures. Using those methods, detailed optimization as e.g. rear spar positions or flap size is only possible within a limited design space. Novel structural concepts such as multi-spar flap layouts or the introduction of composite materials cannot be analyzed using statistical methods and require extended higher level structural modeling. Therefore an interdisciplinary tool chain is developed for extended physics-based wing mass estimation. The tool chain consists of the following components: one central model generator, a structural finite element model, a structural sizing algorithm and loads models for aerodynamic, fuel, landing gear and engine loads. The structural finite element wing model consists of the following main parts: wing box, fixed trailing edge devices, movable trailing edge devices, spoilers, landing gears and engine pylons. The model generator is able to create several different kinds of track kinematics, covering most of the track types used in state-of-the-art aircrafts. To make the complexity of the model generation process feasible for one aircraft designer, a knowledge based approach is chosen. Therefore the central model generator requires a minimum set of easy-to- understand input parameters. This enables the aircraft designer to focus on the design and not on calculating input parameters. To include the tool chain in a wider multidisciplinary aircraft design environment, the aircraft parameterization CPACS (Common Parametric Aircraft Configuration Scheme) is used as central data model for input and output. The developed tool chain is implemented as flexible as possible to enable the designer to analyze also novel structural concepts or wing configurations. On wing configurational level, the tool chain can handle most types of different wing concepts, such as e.g. blended wing bodies, strut-braced wings and box wings. On the structural concepts side, the tool chain is able to handle various different rib and spar layouts and different materials (incl. composites).},

note = {Mike Hackney Best Paper Award},

keywords = {10. Weight Engineering - Aircraft Design, 23. Weight Engineering - Structural Estimation, Mike Hackney Best Paper Award},

pubstate = {published},

tppubtype = {inproceedings}

}