Variation Simulation of Rigid Bodies with Contact Representation

Paper in proceeding, 2026

Variation simulation is widely used for statistical quality control of mechanical assemblies subject to geometric variation. A major challenge lies in accurately modeling contact interactions between rigid components to consistently configure the rigid bodies. This paper presents a Monte-Carlo variation simulation framework that explicitly incorporates rigid-body normal contact using unilateral non-penetration constraints. The proposed method is applied to two reference assemblies and compared against a conventional contactless variation simulation approach. Results show that enforcing contact constraints significantly alters the predicted assembly behavior by reducing the 6σ spread of critical measurement points, while introducing a directional bias along the contact normal reflected by a shift in the mean displacement. These findings demonstrate that contact modeling plays a critical role in realistic variation simulation. The proposed framework provides a physically consistent and computationally efficient basis for contact-aware tolerance analysis of rigid-body assemblies.