重组竹轴向应力-应变关系模型
Model for axial stress-strain relationship of bamboo scrimber

以重组竹为对象，对重组竹的轴向拉伸与压缩应力-应变关系进行研究。通过单向轴向拉伸与压缩试验，研究了重组竹的破坏形态与应力-应变关系特征。试验结果表明：重组竹拉伸的破坏模式表现为脆性拉断，受压破坏模式表现为压屈破坏、剪压破坏和楔形劈裂破坏；重组竹轴向拉伸的应力-应变关系呈线性变化，其受压应力-应变曲线可分为弹性阶段、弹塑性阶段和平台阶段3个阶段。对于重组竹轴向受拉应力-应变关系，建议了线弹性关系模型；对于重组竹轴向受压应力-应变关系，建议了三折线模型、通用函数模型、指数函数模型3个模型，其皆能描述重组竹轴向受压时应力-应变曲线的三个阶段。各个模型的计算结果与试验结果总体吻合度均较好。 The tensile and compressive stress-strain relationships of bamboo scrimber were studied in this paper. The uniaxial longitudinal tension and compression tests were carried out to investigate the failure modes and the characteristics of the stress-strain relationships of bamboo scrimber. The results indicate that the tensile failure modes show as brittle tensile failure, and the compressive failure modes show as buckling failure, shearing failure and wedge split failure. According to the test results, the tensile stress-strain relationship of bamboo scrimber is linear until failure, and the compressive stress-strain curves of bamboo scrimber can be divided into three stages:elastic stage, elastic-plastic stage and platform stage. A linear elastic model was suggested for the tensile tress-strain relationship for bamboo scrimber; three models were presented for the compressive tress-strain relationship, namely trilinear model, general model and exponential model.The results indicate that three presented models can describe the three stages of the stress-strain curves of the bamboo scrimber under axial compression. Totally, the predicted results of the proposed models are in good agreement with the experimental results. 国家自然科学基金（51208262；51778300）；江苏高校优势学科建设工程资助项目（PAPD）；江苏省第五期"333工程"培养资金资助项目（BRA2016421）和青蓝工程项目