一种面向热膨胀性能的公差设计方法

A tolerance design method for thermal expansion performance

双材料点阵是实现热膨胀设计最有效的途径之一,然而制造误差会对热膨胀性能造成影响,传统公差理论无法保证产品性能的精确实现。提出了一种能保证双材料点阵等效热膨胀系数精确实现的功能性公差设计方法。首先,分析尺寸的热膨胀效应,根据结构热膨胀性能的极限情况进行变量分组;然后,分析尺寸敏感度,分别采用逐步降低敏感尺寸的公差等级和优先降低非敏感尺寸的公差等级两种方法对尺寸偏差优化模型进行改进;最后,通过对三种热膨胀性能的胞元进行公差设计,验证了方法的正确性。本文首次考虑了双材料结构的公差设计,建立了公差设计和结构热膨胀性能之间的关系,对双材料点阵的制造与应用具有很大的理论和实际意义。

Dual-material lattice is one of the most effective ways to realize the design of coefficient of thermal expansion,but the thermal expansion performance is affected by manufacturing error,the traditional tolerance theory can’t guarantee the accurate realization of product performance.This paper puts forward a kind of functional tolerance design method that can ensure the equivalent thermal expansion coefficient of the dual-material lattice to be achieved accurately.Firstly,the thermal expansion effect of each size was analyzed,and the variables were grouped according to the limit of the thermal expansion performance of the structure.Then,the size sensitivity was analyzed,and the size deviation optimization model was improved by two methods of gradually decreasing the tolerance level of sensitive size and decreasing the tolerance level of non-sensitive size first.Finally,the correctness of the method was verified by the tolerance design of three kinds of cells with thermal expansion performance.This paper considers the tolerance design of dual-material lattice for the first time,and establishes the relationship between tolerance design and thermal expansion performance of the structure,which is of great theoretical and practical significance to the manufacturing and application of dual-material lattice.