Evaluation of assemblability based on statistical analysis of tolerance propagation

In this paper we present a statistical approach to assemblability evaluation based on tolerance and clearance propagations. Tolerance affect assemblability of an assembly sequence, however, clearance can compensate for tolerance. Assembly planners in the past have assumed nominal dimensions for product components for generating feasible assembly sequences. These sequences, however, may not be assemblable in practice due to propagations and accumulations of tolerances. With this concept of clearance, approaches to compute statistical tolerance and clearance propagations for serial, parallel, and multi-loop chains are proposed. The proposed method can be a valuable tool for CAD/CAM since early detection of assembly problems can significantly reduce the product cost.