本文对传统的四连杆式紧线器进行了空间力系分析,找到了致其破坏的力学因素.并且采用有限元法和应变电测法,确定了紧线器钳体的应变幅值及高应变区域.再按局部应力应变法考察了钳体的损伤容限.使紧线器达到了负荷容量大、重量轻以及安全可靠的设计要求. In this paper, the force analysis of the traditional four-tiered wale is carried out and the mechanical factors causing its failure are found out.The strain amplitudes of the wrenches are determined by finite element method and strain gauging method And high strain area.And then according to the local stress and strain method, the damage tolerance of the caliper body was inspected, which made the wire take-up device meet the design requirements of large load capacity, light weight and safe and reliable.