基于温度历程的高强钢丝应变及应力计算方法

在已有1 770级φp5低松弛预应力钢丝高温力学性能试验研究基础之上,建立了高温下预应力钢丝考虑温度历程的应变及应力计算方法.其中的应变计算方法以钢丝应变变化为研究对象,考虑了钢丝温度变化过程中蠕变、温度膨胀、应力变化及变形模量变化对钢丝应变的影响;应力计算方法以钢丝应力为研究对象,考虑了钢丝温度变化过程中应力松弛、温度膨胀、应变变化及变形模量变化对钢丝应力的影响.通过试验验证了应变及应力计算方法的可行性,结果表明,这两种计算方法可用于预应力结构的抗火性能分析.

Stress and Strain Calculate Methods of High Strength Steel Wire Considering Temperature-Time Path

Based on the experimental research on prestressing steel wire(f_(ptk)=1 770 N/mm~2,d=5 mm,low relaxation of stress) at high temperature,stress and strain calculation methods of high strength steel wire considering temperature-time path was proposed.The strain calculation method,with creep,thermal expansion,stress variation and modulus variety of steel wire at high temperature being taken into account,was centred around the strain of the steel wire at high temperature.While the stress calculation method,with stress relaxation,thermal expansion,strain variation and modulus variety of steel wire at high temperature being taken into account,was centred around the stress of the steel wire at high temperature.These calculation methods were verified to be feasible by experiment and can be utilized in the analysis of fire resistance performance of prestressed structures.