中文摘要：

钢材在单调荷载作用下的本构模型是进行结构分析的基础。为了更为准确地计算高强钢结构响应和分析构件的受力性能，为工程设计人员应用高强钢提供参考，该文在总结已有试验研究、开展大量拉伸试验的基础上，更新了高强钢多折线本构模型的参数，以Ramberg-Osgood模型为基础标定了适用于高强钢的非线性本构模型。通过和试验数据的对比，证明非线性本构模型能够很好地模拟高强钢在单调荷载作用下的应力-应变关系。为了兼顾准确性和效率，该文还提出了修正的多折线本构模型，在反映高强钢非线性的材料性能的同时本构模型也相对简单。

英文摘要：

The constitutive model of steel under monotonic loading is the basis for structure analysis. In order to calculate the response of high-strength steel structures and to analyze the member behaviour more accurately and to give some references to engineers when applying high-strength steel, this paper updated the parameters of the multi-linear constitutive model of high-strength steel and presented a nonlinear constitutive model based on the Ramberg-Osgood model by means of summarizing the experiment results and by carrying out lots of tensile tests. It has been proved that a nonlinear constitutive model could simulate the stress- strain relationship of high-strength steel under monotonic loading well by comparison with the experiment data. Moreover, to give a consideration to both accuracy and efficiency, a revised multi-linear constitutive model is proposed, which could present the nonlinear material property of high-strength steel and show the similarity in the meantime.