EVALUATION OF RESIDUAL STRESS IN A THICK-WALLED TUBE FOR FUNCTIONALLY GRADIENT MATERIAL

功能梯度材料厚壁管残余应力的评估

• 批准号: 04650091
• 负责人: TOYA Masayuki
• 金额: $ 1.34万
• 依托单位: KAGOSHIMA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04650091/
• 关键词: Functionally Gradient Material; Residual Stress; Thermal Stress; Numerical Analysis; Bending; Inverse Problem

A study has been done for examining the residual stress in a thick-walled tube of a functionally gradient material manufactured by a centrifugal method. Duralcan F3D.20S composites that were AL/20vol%SiC were adopted as a master composites. The effectiveness of the curved beam theory considering the gradation of properties was first to eamine by a ring compression test. The circumferential strain generated by residual stress were measured based on the cutting test and the observed strain were in the range of - 750mu strain to 500mu strain. Based on this results, the distribution of residual stress were analyzed as an inverse problem and a numerical analysis was also adopted to solve the thermal deformation of axial symmetry. When the test pieces were cooled uniformly, the yielded stress and strain were changed from compression to tension toward the outside of the tube accompanied with a decrease in a coefficient of thermal expansion., It was concluded that the residual stress were generated by a cooling from a reference temperature of half the melting point to ambient temperature that was about 140K.The residual stress were found to enlarged corresponding to the increase of thermal epansion mismatch and radial thickness.

对离心法制造的梯度功能材料厚壁管的残余应力进行了研究。采用AL/20vol%SiC的Duralcan F3D.20S复合材料作为主复合材料。首次通过环压试验验证了考虑性能分级的曲梁理论的有效性。基于切削试验测量了残余应力产生的周向应变，所观察到的应变在-750 μ应变到500 μ应变的范围内。在此基础上，将残余应力的分布作为反问题进行了分析，并采用数值分析方法求解了轴对称热变形。当试样均匀冷却时，屈服应力和应变从压缩变为朝向管外侧的拉伸，同时热膨胀系数降低。结果表明，残余应力是由参考温度（熔点的一半）冷却到室温（约140 K）产生的，残余应力随热膨胀失配和径向厚度的增加而增大。