Full-Range Compressive Stress-Strain Curves for Cold-Formed 304 Stainless Steel Circular Hollow Sections After Exposure to Vacuum Brazing

作     者：Bin Hu Yang Jin Lin-Zhi Wui 无

作者机构：Center for Composite Materials Harbin Institute of Technology Harbin 150001 China Key Laboratory of Advanced Ship Materials and Mechanics College of Aerospace and Civil Engineering Harbin Engineering University Harbin 150001 China 

出 版 物：《Acta Mechanica Solida Sinica》 (固体力学学报（英文版）)

年 卷 期：2018年第31卷第5期

页      面：557-572页

核心收录：

学科分类：082304[工学-载运工具运用工程] 08[工学] 080203[工学-机械设计及理论] 080204[工学-车辆工程] 0802[工学-机械工程] 0823[工学-交通运输工程] 

基　　金：The work was supported by the National Natural Science Foundation of China under Grant Nos. 11432004 and 11421091 

主　　题：Compression test Stress-strain curve Cold-formed 304 Stainless steel Circular hollow section (CHS) Post-brazing 

摘      要：With the rapid development of microscale cellular structures, the small-diameter cold-formed welded stainless steel tubes have recently been used for creating the metallic lat- tice topologies with high mechanical properties. In this paper, to obtain the accurate material properties of the circular hollow section （CHS） under pure compression, a series of concentric compression tests are conducted on the millimeter-scale cold-formed 304 stainless steel circu- lar tubular stub columns after exposure to a vacuum brazing process. The tests cover a total of 18 small-diameter stub tubes with measured thickness-to-diameter ratios （t/D） from 0.023 to 0.201. A generalized three-stage nominal stress-strain model is developed for describing the compressive behavior of the post-brazing CHSs over the full strain range. This mechanical model is especially applicable to computer code implementation. Hence, an interactive computer pro- gram is developed to simultaneously optimize three strain hardening exponents （n1, n2, n3） in the expression of the model to produce the stress-strain curve capable of accurately replicating the test data. To further reduce the number of the model and material parameters on which this model depends, this paper also develops five expressions for determining the 2.5% proof stress （ap2）, n2, the ultimate compressive strength （σp3）, n3, and the ultimate plastic strain （p3%） for given experimental values of three basic material parameters （E0, σ0.01, σ0.2）. These expressions are validated to he effective for the CHSs with t/D 〉_ 0.027. The analytically predicted full-range stress-strain curves have generally shown close agreement with the ones obtained experimentally.