Abstract：The unfolding accuracy of Invar alloy mould plate with double curvature has an important influence on the accurate cutting of the workpiece and the amount of machining work after pre-forming. Based on the study of forming process and deformation distribution of hyperbolic sheet, a development method for the plate with double curvature based on small triangle is proposed. The surface is divided into several strips and small triangles, and then the small triangles are unfolded and spliced to get the unfolded shape. The key is the splicing method and the treatment of overlapping and gap. On this basis, the development software is developed and verified in actual production. Based on the development processing of 121 plates in 32 sets of dies, it is found that only 5–10mm allowance is needed for the workpiece processed by this method, which is far less than the 20–40mm allowance required by the traditional development method, which can significantly reduce the subsequent machining workload.
2022, 
