1153. Dynamic Loads and Airplane Structural Weight

Paper

Abstract

The development of aircraft with highly efficient structures has increased the need for including the influence of dynamic response in their design, and has brought into prominence the dynamic loads. specialist. The present paper describes various types of dynamic loadings and Indicates their source and potent i a l impact on aircraft structural weight. Delineation is made between static and dynamic loading, and appropriate definitions introduced to simplify insofar as possible the complex subject matter.
Design criteria, their sQuTces, and their application are noted wherein the consideration of structural dynamic response has added complexity and structural weight to the aircraft and its systems. The discussion includes reference t o dynamic test and the correlation of test results t o theory.
Extensive reference is made t o the influence of structural dynamics on the design of the Lockheed L-1011 TriStar, with lesser reference t o other Lockheed commercial and military aircraft. Although the emphasis is mainly on the design of large aircraft, general aviation vehicles are included in the presentation.
A brief review is given of two current research programs, covering active controls technology and crashworthiness considerations. The first program Involves a study of the interaction of’ the control systems with the dynamics of the structure, and indicates a potential f o r structural weight savings. The second describes work being done to improve survivability In aircraft crashes with consideration of more advantageous structural weight distribution.
The presentation is largely in lay terns, directed t o those less familiar with engineering, minimizing the use of mathematics and highly technical terminology.