舰用燃气轮机支架缩比模型试验方法研究

Scaled model and test method for marine gas turbine mount system

关键部件冲击试验是舰用燃气轮机抗冲击设计的必要考核手段。针对某燃气轮机支架系统抗冲击试验问题,首先,采用相似理论与等效冲击相结合的方法,选取与支架系统动力特性相关的物理量并推出相似关系。其次,确定支架冲击试验材料并通过试验得到力学特性,分析其受到的载荷、固有频率及模态振型。最后,提出一种燃机支架系统的缩比试验模型及试验方法,并通过有限元模型进行模态分析和冲击仿真计算,验证了支架缩比试验模型与原模型的等效性。结果表明:缩比试验模型一阶、二阶固有频率与原模型的相对误差均在10%以内;相对位移响应误差为13.69%,绝对加速度响应误差为3.18%,相对误差均在20%内,满足工程要求。验证了支架系统缩比模型及试验方法的有效性,为燃机支架系统抗冲击试验提供技术支撑。

Shock tests of key components are a necessary examine means to assess anti-shock design of marine gas turbine.Here,aiming at shock resistance test of a certain gas turbine mount system,firstly,the method of combining the similarity theory and equivalent shock was used to choose physical quantities related to dynamic characteristics of the mount system,and deduce their similarity relations.Secondly,shock test material of support was determined,and its mechanical properties were obtained through tests.Load,natural frequencies and modal shapes of the mount system were analyzed.Finally,a scaled test model and test method for gas turbine mount system were proposed,and the equivalence between the scaled test model and the original model was verified using modal analysis and shock simulation calculation with the mount system’s finite element model.The results showed that relative errors between the first order and second order natural frequencies of the scaled test model and the original model are within 10%,their displacement responses’relative errors are 13.69%,their acceleration responses’absolute errors are 3.18%and relative errors are within 20%to meet engineering requirements;the effectiveness of the scaled model and test method of mount system is verified;the study results can provide technical support for shock resistance test of gas turbine mount system.