Experiment Study On The Complex Property Of Structural Member Acted On By Earthquake Force

Three loading paths including rectangle path,diamond path and ellipse path are applied to the reinforced concrete columns in quasi-static test.The actuators and displacement sensors are installed i on the specimens.The control softwares are TUSTand TUMT in the test.The conlusions based on the test results are as follows:1,The specimens have more hysteresis dissipated energy under axial forces than those under torsional forces.2,The torsional moment value decreases rapidly when exceeding the maximum ,whose characteristic reveals brittleness.3,The damage caused by the torsion is larger than under axial force at the same applied loading.The damage evaluation must refer to the on-site situation, because the test results are hard to compare under different loading paths. With the enlargement of displacement, the damage quickens.4,The energy curves derived from the data tested by application of different loading on columns are different,therefore,the evaluation of damage grades must be founded on the entire test results.5,The curves of torsional hysteresis dissipated energy demonstrate long slippage and hold together in the middle.On the contrary, the curves of momental hysteresis dissipated energy,which is like shuttle shape, consume much more energy than those curves.With the development of the applied force, the torsional resistant ability attenuates far greatly and its ductibility becomes worse. The rigidity degenerates rapidly when the maximal torsion moment exceeds the peak value,which makes for a brittle damage to these reinforced concrete columns.6,The displacement data measured in the test are much larger than those calculated by the formulae in reinforced concrete code, especially after cracks produced. The effects of torsion and shear forces affecting columns should be think over on the condition of torsion force playing a much important role.