Elasto-plastic time-history analysis of holistic space truss structure with inclined plane under earthquake

The space truss with inclined plane is placed inclined and the supporting columns have large elevation difference,the mass and stiffness of holistic structure is evidently asymmetric. The paper carries on elasto-plastic time-history analysis for inclined space trusse,and compares with plane space truss in respect of stress features. The analysis shows: the whole stress features of inclined space trusses have large distinguish between x,y direstions. When inclined space trusses vibrate in direction of y( direction of second vibration mode) ,the high-side and low-side supporting columns and space truss constitute a solid lateral resistant system,so the shear forces is distributed according to lateral stiffness of supporting columns under earthquake action in direction of y; when inclined space trusses vibrate in direction of x( direction of first vibration mode) ,the low-side columns don't constrain high-side columns powerfully,shear forces in direction of x are determinated by loads that every column bear based on D'Alembert Principle; because the axial forces that are passed from high-side and low-side columns to top chord and web member have much difference,the internal force distribution of inclined space truss has this unique character under earthquake action.