不锈钢管道径向压接模具的设计、仿真与寿命验证

Design, Simulation and Life Verification of Radial Crimping Mold for Stainless Steel Piping

摘要: 针对薄壁不锈钢管卡压连接过程中国产管路材料与尺寸离散度大、进口模具难以适配的问题，本文以DN25径向压接模具为对象，开展理论受力分析、CAE有限元仿真与寿命试验。首先建立包含摩擦与接触的卡压力学模型，并识别钳口下端面、上下端面与上端面三类极限接触工况。随后在42CrMo材料假设下开展静力学有限元，初始模型在上端面接触时最大等效应力达1130 MPa，存在失效风险。考虑配合间隙与弹性形变对力臂与接触角的影响后，修正理论参数并二次仿真，最大应力降至867 MPa。基于应力分布图，对模具厚度、钳口倒角与过渡圆角进行优化，最不利工况的峰值应力进一步下降至781 MPa (约为材料屈服强度930 MPa的84%)。在3.2 t推力的满载循环试验中，优化结构实现26,276次无事故循环，超过20,000次设计寿命。研究结果为系列规格卡压模具的参数化设计与快速迭代提供了可复用的方法论与数据依据。

Abstract: To address the mismatch between imported dies and domestic thin‑wall stainless pipes with large variability, this study investigates a DN25 radial crimping die through theoretical analysis, CAE simulations, and fatigue tests. First, a card tribology model that includes friction and contact was established and three types of limiting contact conditions are identified: the lower end surface of the jaws, the upper and lower end surfaces, and the upper end surface. Subsequently, static finite element analysis was performed under the assumption of 42CrMo material. The initial model showed a maximum equivalent stress of 1130 MPa at the upper surface contact, indicating a risk of failure. After considering the influence of fitting clearance and elastic deformation on the force arm and contact angle, the theoretical parameters were modified and a second simulation was conducted, reducing the maximum stress to 867 MPa. Based on the stress distribution map, the mold thickness, jaw chamfer, and transition fillet were optimized, further reducing the peak stress under the most unfavorable working conditions to 781 MPa (approximately 84% of the material’s yield strength of 930 MPa). In the full-load cyclic test with a 3.2 t thrust force, the optimized structure achieved 26,276 cycles without failure, exceeding the designed lifespan of 20,000 cycles. The research results provide a reusable methodology and data basis for the parametric design and rapid iteration of a series of crimping molds.