Probabilistics finite element analysis for double layer steel space truss

摘要

In this thesis, a double layer steel space truss was analyzed by using ProbabilisticudMethod with ANSYS program and validate by Finite Element Method with manualudcalculation. This analysis is to determine the behaviors of the double layer steel spaceudtruss. Besides that, it is also to study of the probabilistic response analysis and inputudsensitivities of the double layer steel space truss. Nowadays space truss is widely usedudin many types of construction that included stadium, shopping mall, tower, stage, roofudstructure and also home design. The difference texture of assembly will definitely udbeautify a building or a place. In this research structure a 4 x 4 xud0.5udmeter for the length,udwidth and height had been used, there have 4 supports at the bottom of the structure, udand resist of a total of 16 point loads on the top of the structure. The circular hollowudcross section was used for the horizontal member and diagonal member for the structure.udA 275N/mmud2ud of yield strength was choose for the steel space truss. The material and udgeometry of the space truss was satisfying for this research since it passes all the designudcriteria in designing for tensile, compression and also buckling. The ANSYS resultsudshow very good agreement with manual calculation results. From the results ofudsimulation, we get to know the real behavior of the structure under the applied loads.udFrom probabilistic analysis, we got the results of cumulative distribution function,udhistogram plot, sensitivity plot and simple history plot by 10000 times of simulation. In udthe simulation results, 5udinputs were assigned to get the probabilistic maximumuddeflection, axial stress and axial elastic strain. Theud5udinputs are force, outer diameter ofudhorizontal member, outer diameter of diagonal member, thickness of horizontal member udand thickness of diagonal member. Results from ANSYS program indicated that theudmaximum deflection is 7.74mm, maximum axial stress is 141.16MPa, and maximum udaxial elastic strain is 0.6722E-03.