平面混凝土框架结构地震损伤机理研究

桥梁结构振动台试验表明,在上部质量较重的梁柱组合框架结构中,柱子的抗剪性能受自重压力的影响很大,轴力在一定程度上加剧了抗剪能力的衰减,混凝土结构的地震损伤机理是压剪耦合作用下材料性能的劣化,表现为混凝土拉压损伤导致结构刚度的折减和承载能力的降低。文章采用拉压损伤变量分析混凝土材料的损伤机制,并考虑混凝土的拉压异性效应和随动强化效应,给出了相应的弹塑性损伤本构,模拟了混凝土框架结构在地震作用下的非线性响应过程。破损区域损伤变量时程曲线表明,混凝土柱子是在剪切造成的拉伸和轴向压缩损伤作用下发生破坏而退出工作的。

Analysis on Damage Mechanism by Earthquake of Plane Concrete Frame Structure

Shaking table test of bridge structure indicates that the shear capacity may he greatly cooperated to the gravity axial forces in the beam-column structure with weightier upper structure.The axial force accelerates the reduction of shear capacity of the columns.The damage mechanism by earthquake of concrete structure is tire degradation of concrete properties under coupling action between the axial and the shear forces,which introduces stiffness delimitation and bearing loss of the system.In this essay,the author simulates the responses of a(Jane concrete frame excited by seismic loading based on elastoplastic scalar damage constitutive model with the two damage variables corresponding to tensile and compression conditions respectively.The damage variables curves in the area concerned of the structures indicate the cause of collapse is the tensile damage from shear loading and the compressive damage from axial loading.The strain energy norm expression is used as damage criteria during analysis with difference between tension and compression and kinetic hardening being considered.