薄壁构件中应力释放和表面应力对变形的影响

Effect of stress release and surface stress on deformation of thin-wall component

铝合金厚板在被切割或是进行材料去除加工后,其加工面附近的应力被极大地释放,并与本身的初始应力形成较大的应力梯度。薄壁构件成型后,其加工面附近的应力即是如此,而且加工所形成的加工应力附着在表面,综合作用造成了构件应力分布的不均匀,这是构件加工后容易产生变形的直接原因。以7075铝合金板材进行加工仿真和试样试验研究,分析了上述两类应力分布现象,在初始应力的释放和加工表面应力共同影响下造成了构件的变形,并提出了减小变形的措施。

The stress is greatly release nearby the cutting section or machining-out section of aluminum alloy plat, and a large stress gradient is being formed comparing with the primary stress. The stress nearby the processing section of formed thin-wall component presents the same gradient, and the forming stress stuck to the surface, comprehensive actions made stress of the component distributed unevenly, which is the direct reason causing the processed component being deformed easily. The processing of 7075 aluminum alloy sheet has been used for simulating and experiment researching, through that the stress distribution morphology of above mentioned two types of stress have been analyzed. The result shows that the deformation of the component is happened under the common action of primary stress releasing and processing surface stress. The measures for reducing the deformation of components has been put forward.