Autoclave process is widely used in manufacturing processes for thermosetting matrix composite materials. During the process, the non-uniformity of temperature distribution in autoclave may result in non-synchronous curing of composite, which in turn reduces the mechanical properties of composite parts. In order to improve the curing performance, design optimization of autoclave molds has to be performed. In this paper, a finite volume method based numerical model is established to simulate the temperature distribution inside an autoclave and it is verified by known experimental data. Then, a typical mold structure, which is covered with composites and simplified auxiliary materials, is introduced to the numerical model. Moreover, a method which combines the numerical model with the genetic algorithm is presented to optimize design parameters of the substructure of mold with an aim of improving the synchronism of curing. The maximum standard deviation of degree of cure in composite parts is adopted as the objective, while the deformation of the mold under hoisting situation is considered as the constraint. The result shows that the maximum standard deviation of degree of cure in composite parts is improved as much as 17.21%, which indicates that better synchronism of curing is achieved with the presented method.

Due to small production volume in aircraft industry, the available information of variation sources is often not enough to make assumptions on their probabilistic characteristics, especially in the stage of prototype manufacturing. To deal with the problem, an assembly variation modeling and analysis method based on the elasticity mechanics and interval approach is proposed for aircraft assembly. First, variation sources are modeled as bounded convex sets, which are defined as interval structural parameters in interval arithmetic. Then, variation modeling and analysis are successively implemented using the method of influence coefficient and interval arithmetic. After that, a uniform-splitting method is applied to achieve the refinement of the interval extension in variation analysis. To reduce the complexity of the finite element analysis and assembly variation computation, part deformation forms including warpage and torsion are concisely characterized with angle instead of the deviations of isolated key points on the part. The comparison of the assembly variations estimated with the proposed variation analysis method and actual experiment results verifies the effectiveness of the constructed assembly variation model and the proposed method. The interval approach–based assembly variation analysis method is a good complement to traditional probabilistic approach–based methods for compliant assembly systems, which is suited for linear and linearized nonlinear assembly systems. The proposed method provides an improved understanding of the application of compliant assembly variation analysis methods in aircraft manufacturing.