A Deviation Propagation Graph Model and Deviation Propagation Computation Method for Rigid–Flexible Hybrid Assembly

Abstract

In box-type spacecraft structures, machine tools, and similar complex products, assembly variation transfer is governed jointly by multilevel assembly hierarchy, parallel support chains, and the elastic response of compliant parts. Under such conditions, classical formulations based on a single tolerance chain or rigid-body accumulation cannot preserve assembly topology, part-level tolerance relations, and compliant coupling within a unified representation. This paper presents a graph-based method for rigid-flexible hybrid assembly variation analysis. An assembly directed graph (ADG) is used at the assembly level to encode assembly sequence, locating datums, and interface dependency, while a dimension and tolerance propagation graph (DTPG) is used at the part level to organize feature-level relations among dimensions, geometric tolerances, and measured deviations. A propagation-path subgraph is then extracted on the ADG for a designated source datum and target functional feature, and coupled with the relevant DTPGs to generate an assembly relation propagation graph based on functional element pairs (FEPs). In this way, all effective parallel transmission branches are preserved explicitly and remain available for branch-wise comparison and variation tracing. A plate-type rigid-flexible hybrid assembly case demonstrates that the proposed method preserves the effective transfer structure associated with the target feature and provides a clear basis for dominant-branch identification and assembly process adjustment.

Keywords: Rigid-flexible Hybrid Assembly, Deviation Propagation, Graph-based Modeling, Assembly Directed Graph, Propagation-path Subgraph

DOI: 10.54941/ahfe1007449