This paper reports an experimental and numerical investigation into the cross-section behaviour and resistances of press-braked stainless steel channel sections under combined compression and major-axis bending moment. A testing programme was firstly conducted, including initial local geometric imperfection measurements and major-axis eccentric compression tests on ten press-braked stainless steel channel section stub column specimens. Following the testing programme, a numerical modelling programme was performed, where finite element models were developed and validated against the test results and then adopted to perform parametric studies to generate further numerical data over a wide range of cross-section dimensions and initial loading eccentricities. Based on the obtained test and numerical data, the existing design interaction curves, as given in the European code, American specification and Australian/New Zealand standard, were assessed and shown to result in conservative cross-section resistance predictions for press-braked stainless steel channel sections under major-axis combined loading. The conservatism of the codified design interaction curves stems from the conservative end points (i.e. cross-section resistances under pure compression and pure bending), which are determined without considering the effect of material strain hardening, and the inefficient linear shape, which ignores the effect of stress redistribution. Improved design interaction curves were proposed through the adoption of (i) more accurate end points, which are calculated with a rational exploitation of material strain hardening by continuous strength method and (ii) more efficient nonlinear shape, which allows for the stress redistribution. The proposed design interaction curves were shown to result in substantially more accurate resistance predictions for press-braked stainless steel channel sections under major-axis combined loading than their codified counterparts. The reliability of the proposed design interaction curves was confirmed by means of statistical analyses.

本文报告了在组合压缩和长轴弯矩下压力制动不锈钢通道截面的横截面行为和阻力的实验和数值研究。首先进行了一个测试程序，包括对十个压弯不锈钢通道截面短柱试样的初始局部几何缺陷测量和长轴偏心压缩测试。在测试程序之后，执行了一个数值建模程序，其中开发了有限元模型并根据测试结果进行了验证，然后用于执行参数研究，以在广泛的横截面尺寸和初始加载偏心率范围内生成进一步的数值数据。基于获得的试验和数值数据，现有的设计相互作用曲线，如欧洲规范、美国规范和澳大利亚/新西兰标准中给出的那样，经过评估并显示出在长轴组合载荷下对压弯不锈钢槽钢截面进行保守的截面阻力预测。编码设计相互作用曲线的保守性源于保守端点（即纯压缩和纯弯曲下的横截面阻力），其确定没有考虑材料应变硬化的影响，以及无效率的线性形状，忽略了影响应力再分配。通过采用 (i) 更准确的端点，通过连续强度方法合理利用材料应变硬化来计算和 (ii) 更有效的非线性形状，提出了改进的设计交互曲线，这允许应力重新分布。与编纂的对应曲线相比，所提出的设计相互作用曲线在长轴联合载荷下对压制动不锈钢通道截面的阻力预测要准确得多。通过统计分析证实了所提出的设计相互作用曲线的可靠性。