高强度钢材低温力学性能试验研究与预测模型

Experimental Study and Prediction Model of Low Temperature Mechanical Properties of High-Strength Steel

在极地严寒地区工程中应用高强钢可节省用钢量,减少低温严酷环境下钢结构制作、运输和安装成本.为研究HG785高强钢在极地低温环境下的力学性能,对考虑2种厚度和5种低温环境的高强钢试样开展单轴拉伸试验.试验结果表明,极地低温环境下HG785高强钢的弹性模量、屈服强度和极限抗拉强度相较于其在25℃常温环境下有所提高,失效模式均为颈缩延性破坏并无脆断倾向.采用全子集法对试验结果进行回归分析,建立极地低温环境下高强钢力学性能指标预测模型,可指导高强钢在结构构件、节点与体系中的合理高效应用,为高强钢结构在极地低温地区服役与结构设计优化策略决策提供理论依据.

The application of high-strength steel in extremely cold polar regions can reduce steel consumption and save the cost of fabrication,transportation,and installation of steel structures in the harsh low-temperature environment.In order to study the mechanical properties of HG785 high-strength steel under polar low-temperature conditions,uniaxial tensile tests were conducted on high-strength steel coupons by considering two thicknesses and five low-temperature cases.It was found that the elastic modulus,yield strength,and ultimate tensile strength of HG785 high-strength steel in polar low-temperature environment are higher than those at an ambient temperature of 25 C.All tensile coupon specimens failed by traditional necking in a ductile manner without brittle failure tendency.Based on the test results,accurate prediction models for mechanical properties of HG785 high-strength steel in polar low-temperature environment were established by the best subset regression analysis.This will facilitate the application of high-strength steel in the design of structural members,joints,and systems in an efficient manner,and provide theoretical support for the promotion of high-strength steel structures in polar low-temperature regions.