吊杆退化钢丝损伤模型及双折线近似计算

Damage Model and Bilinear Approximation of Deteriorated Wires in Suspenders

摘要:

提出了新的钢丝损伤模型及双折线近似计算方法.根据退化钢丝单调拉伸试验数据和有限元模拟结果,以钢丝荷载—位移包络图,建立了包含强度、刚度、延性折减及反映环境腐蚀和加载历程等影响因素的损伤模型.结合精确积分及S.M.Elachachi本构方程损伤计算结果,给出了新的双折线近似计算方法.依据吊杆截面内钢丝锈蚀分布规律,确立吊杆损伤因子,并进行了模型验证和参数分析.结果表明,钢丝损伤后,力学性能退化较明显;所建立的吊杆损伤因子,反映了各力学性能的退化,较合理.

Abstract:

Based on the mechanical properties of deteriorated wires which examined by experimental tests and FEM simulation,a new damage model and bilinear approximation of deteriorated wires in suspenders are proposed according to force-displacement envelope of deteriorated wires.The model is cumulative and capable of combining the real constitutive relations of wires,strength,stiffness,ductility,corrosion,and loading history.The new bilinear approximation of the deteriorated wires is advanced based on the exact solutions of integral method and S.M.Elachachi constitutive method.Furthermore,the damage indicator of suspender is established combined with the corrosion distribution and damage indicators of wires.Finally,the rationalization of the proposed model is validated and the sensibility of parameters is illustrated.It is found that the mechanical properties of wires degrade significantly with the corrosion and actual load history.In addition,the damage indicator of suspender is reasonable which reflects the degradation in strength,stiffness and limit strain.