456. Basic and Secondary Structural Weight of Expandable Space Structures

Paper

Abstract

A large number of weight parameters were studied under the direction of the Office of Advance Research and Technology, NASA Headquarters, Washington, D. C.’ The basic weight parameters were material properties, shape of vehicle, method of construction, pressure, volume, and safety f a c t o r while the secondary parameters were elastomer, seams, cutout and joint reinforcement, pressurization system, partions , and dynamic loadings, It was found t h a t a modification, of the isotensoid weight equation could be used ts study the b a s i c w e i g h t parameters The basic structural weight, WB, is the weight of structural material required to support the pressure induced stresses, C is a coefficient based on shape and method of construction (C= 3 for isotensolid structures) p i s the pressure, V is the volume, n is t h e f a c t o r of safety, and k is the strength-weight ratio of the construction material. Values of C are calculated for the sphere, spheroid, cylinder, torus and combinations, as well as f o r p a r t i a l volumes of these shapes. The weight of other combinations may be determined from the sum of weights of the component partial volumes. The minimum weight is determined with optimum values of C and the maximum by 6 = 30 Values of kc f o r many important materials along with the constant C, make it easy to determine the basic structural weight of any pressure stabilized surface of revolution. The weight of elastomer or binder, tut out reinforced joints, partitions, and pressurization systems have all been shown to be directly dependent upon the basic structural weight equation. Two of these, elastomer and pressurization system, can each equal the basic weight of elastomeric manned vehicles.