Advancing Predictive Approaches for Stress-Strain Models of Stainless Steels in Cold-Formed Corner Regions

Accurate modeling of stainless steel behavior in cold-formed corner regions requires reliable input material parameters, which can be obtained through corner coupon tests. However, the implementation of existing stress-strain models requires key material parameters that are often unavailable due to the challenges of conducting corner coupon tests. To support more generalized applications of stress-strain models and reduce reliance on physical testing, a comprehensive database comprising 321 corner coupon test results and 93 full-range stress-strain curves was collected from 58 published sources, covering the most widely used structural stainless steel types, including austenitic, duplex, and ferritic grades. Subsequently, the applicability of existing predictive models for estimating essential material parameters was assessed and modified or newly developed equations were proposed where improved accuracy was needed. Based on either measured or predicted material inputs, stress-strain curves were generated by adopting a one-stage Ma-Chan-Young model and a modified two-stage Ramberg–Osgood model, and were validated against experimental data. The evaluation results confirm that the proposed predictive framework can reliably capture the nonlinear stainless steel material behavior in cold-formed corner regions, even in the absence of direct test data, and is suitable for use in numerical simulations and structural design involving cold-formed stainless steel structures.