Inelastic behavior of partially restrained steel frames using parallel processing and supercomputers

The inelastic behavior and ultimate load capacity of individual steel beams and beam columns has been extensively studied in the last two decades. However, the advanced inelastic analysis of partially restrained planar steel frames has been limited to small scale structures. In addition, analytic models for structural members commonly utilize concentrated plasticity and interaction surfaces to simulate inelastic behavior of the members in lieu of the more realistic spread of plasticity model. Furthermore, advanced analysis of large planar steel frames has not been attempted due to limitations in computer memory and speed. Advances in computational technology, mainly the advent of vector and parallel processing and nonlinear solution techniques, has allowed problems of unprecedented size and complexity to be solved successfully in various areas of science and engineering. Many limitations to the types of analysis and size of structures analyzed no longer exist. However, no parallel and vector processing techniques have been implemented in the study of the inelastic behavior and ultimate load capacity of large scale partially restrained planar steel frames. A finite element capable of modeling distributed inelastic behavior, residual stresses and partial connection restraint is developed and implemented in a computer program for the inelastic analysis of structural steel frames. The constant work algorithm is utilized to trace the full nonlinear load deflection response of large structural steel frames including ultimate loads and post-critical response. Several structural steel frames are analyzed and the effects of connection restraint, proportional and nonproportional loads are quantified and discussed. The implementation of vectorization and parallel processing utilizing the method of substructures is evaluated. Code performance including speed up and efficiency is presented and discussed