Closed-form approach to checking frame design

摘要

This brief report contains calculations of deflections and stresses of the support frame on the XMM project. The goal is to provide an independent view of structural integrity of the frame utilizing a noncomputer approach to design based on elementary closed form solutions and approximate models of mechanical and structural behavior. It is recognized that full confidence can only be assured when computer generated results pertaining to the critical areas and features of the integrating structure can be enveloped by the bracketing solutions. Although the computer solutions have come from the three independent sources, this report utilizes the numerical values from the LLNL studies represented by the computer runs and analysis of the critical elements of the frame. Since the frame geometry, deformation patterns, and the nature of loading are highly complex, this study is restricted to simplified models of selected areas of the structure which can be handled by the conventional formulas and reasonable approximations. This report contains some comments related to material properties, stress concentration, and elements of fracture mechanics directly applicable to frame analysis and design. Such topics and parameters fall usually outside the finite element modeling, but they can have a crucial influence on the mechanical and structural performance of the systems at hand.