中文摘要：

参数的传递在装配件变型设计中非常重要，而构造尺寸约束方程式是实现参数传递的有效方法。通过分析装配约束的特点，阐明了装配约束语义的表达和装配约束关系的定义。构造了基于装配语义和约束关系的装配约束库。在装配语义表达和装配约束关系定义的基础上，对适合于装配约束库的相似性算法进行了研究，提出了基于装配约束库的配合关系相似度算法，并实现了一定程度上的尺寸约束自动生成。通过具体事例对该算法进行了验证和实现。

英文摘要：

Parameter transfer is very important in assembly variant design, and building equation is an effective method in realizing parameter transfer. By analyzing characteristics of assembly constraints, expression of assembly semantics and definition of assembly constraint relation are illustrated. Assembly constraints library base on assem- bly semantics and constraint relations is constructed, of which structure, function and contents are briefly de- scribed. Based on the expression of assembly semantics and definition of assembly constraint relation, the similarity algorithm of constraint relations is analyzed and studied, the formula of similarity suitable to assembly constraints li- brary is deduced. And automatic generation of dimension constraint is realized in a certain degree. The method is verified and realized by a concrete example.