| 陈志勇,祝恩淳,潘景龙.复杂应力状态下木材力学性能的数值模拟[J].计算力学学报,2011,28(4):629~634,640 |
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| 复杂应力状态下木材力学性能的数值模拟 |
| Numerical simulation of mechanical behaviour of wood under complex stress |
| 投稿时间：2010-06-25 修订日期：2011-02-15 |
| DOI：10.7511/jslx201104024 |
| 中文关键词: 木材 正交各向异性 本构关系 数值模拟 |
| 英文关键词:wood orthotropy constitutive relationship numerical simulation |
| 基金项目:国家自然科学基金(50878067)资助项目. |
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| 中文摘要: |
| 针对木材复杂的各向异性材料特点,建立了能反映木材正交各向异性弹性、抗拉和抗压强度不等、抗拉或抗剪时发生脆性破坏而受压时发生塑性变形等特性的本构模型。将木材弹性应力—应变关系简化为正交各向异性;选用Yamada-Sun强度准则来判断木材抗压时是否屈服,抗拉或抗剪时是否发生应变软化;通过引入损伤因子和弹性应变能,建立了木材发生脆性破坏时的应变软化模型;由屈服函数根据塑性一致性条件推导得木材抗压塑性发展的流动准则;通过设置初始屈服面和最终屈服面并约束屈服面由前者向后者转移来描述木材应变硬化,和横纹承压时的二次应变硬化。编制了用户子程序实现木材本构模型在ABAQUS的嵌入。通过有限元模拟结果与试验结果和Hankinson公式计算结果的对比,验证了所建本构模型是有效可行的。 |
| 英文摘要: |
| A constitutive model of wood suitable for FE modeling of the structures was developed. In the model, wood is orthotropically elastic with different strengths in compression and tension; wood exhibits brittle failure under tension or shear, but yields under compression. The orthotropic symmetry theory was employed to express the relationship between elastic stress and strain. Yamada-Sun criterion was used to judge yield of wood in compression and strain-softening of wood in tension and shear. The strain-softening model of wood was established by introducing the damage factor and the elastic strain energy. The flow rule was derived by yield function according to plastic consistency condition. The strain hardening and the secondary strain hardening of compression perpendicular to grain were modeled by controlling the transition of yield surface from initial yield surface to ultimate yield surface. A user-defined subroutine VUMAT was encoded to include the material constitutive model of wood into ABAQUS, and two FE models were developed to simulate the behaviour of wood in compression and tension, including tension and compression at angle to grain. The constitutive relationship and the FE model were validated by comparison of the numerical results with experimental results and Hankinson strength theory of wood. |
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