Yu Simiao, Cai Lixun, Wang Ling, Lang Lin
School of Architecture and Civil Engineering, Xihua University, Chengdu 610039, China.
Applied Mechanics and Structure Safety Key Laboratory of Sichuan Province, School of Mechanics and Aerospace Engineering, Southwest Jiaotong University, Chengdu 610031, China.
Materials (Basel). 2023 Jan 17;16(3):892. doi: 10.3390/ma16030892.
Due to the unique structure of tensile sheet specimens with a circular hole (CHS specimen), a novel method is proposed to predict the large-range uniaxial stress-strain relations of elastic-plastic materials analytically. Based on the energy equivalence principle, a load-displacement semi-analytical model of the CHS specimen is proposed. Subsequently, a semi-analytical model of constitutive parameters of elastic-plastic materials is developed by virtue of the load-displacement relation of the CHS specimen, and the prediction of the material's stress-strain relations is obtained. To examine the validity of the models, numerical simulations with a series of materials were performed. The results demonstrated that the dimensionless load-displacement curves and stress-strain relations obtained using the proposed models correspond well with those obtained using finite element analysis. In addition, tensile tests were performed on the CHS specimen for four elastic-plastic materials (T225 titanium alloy, 6061 aluminum alloy, Q345 steel, and 3Cr13 steel), and the validity of the models is also verified by the experimental results. Compared with the conventional uniaxial tensile tests, the stress-strain relation of elastic-plastic material captured by the novel method corresponds to a larger strain, which is of great importance for engineering design and safety assessment.
由于带有圆孔的拉伸薄板试样（CHS试样）的独特结构，提出了一种新方法来解析预测弹塑性材料的大范围单轴应力-应变关系。基于能量等效原理，提出了CHS试样的载荷-位移半解析模型。随后，借助CHS试样的载荷-位移关系，建立了弹塑性材料本构参数的半解析模型，并得到了材料应力-应变关系的预测结果。为检验模型的有效性，对一系列材料进行了数值模拟。结果表明，使用所提模型得到的无量纲载荷-位移曲线和应力-应变关系与有限元分析得到的结果吻合良好。此外，对四种弹塑性材料（T225钛合金、6061铝合金、Q345钢和3Cr13钢）的CHS试样进行了拉伸试验，试验结果也验证了模型的有效性。与传统单轴拉伸试验相比，新方法捕捉到的弹塑性材料应力-应变关系对应的应变更大，这对工程设计和安全评估具有重要意义。
