| Force testing frame is based on the original bogie frame. According to the test requirements of the bogie load, structure of the bogie is partially modified and is constructed with properly bridging form. It has the function of force testing and will not affect the normal use of the framework.The main purpose of frame load testing is to establish the load spectrum which has reliable design and evaluation for the fatigue of the frame. We adopt the force testing frame method to measure the load of frame, which has great advantage on the construction of the load spectrum of the frame: test load has the characteristic of static equivalent. Its response and the dynamic stress of frame fatigue's key area which has conjunction with the test load has the same attribute, the relationship between the test load, relating response and the dynamic stress shows quasi-static transmission, and it can be demarcated exactly in the laboratory.For high-speed train bogie frame, the frequency of load-induced disturbance of the framework is close to the natural frequency of elastic vibration of the framework. As a result, the relationship between the load and dynamic stress of framework generally shows dynamic delivery. The load spectrum should meet the requirement of reliability design and evaluation of framework's fatigue. Therefore, for the establishment of high-speed train bogie frame's load spectrum, it is a direct and reliable technical method to adopt the force testing frame to measure the load of the frame.The design of framework needs to solve two problems: firstly, achieving reliable purification of load demarcation, namely, decoupling the issue of load demarcation; secondly, protecting the load measurement accuracy, namely, the issue of signal-to-noise ratio. Based on the analysis of the character of response distribution which corresponds with the load demarcation, this article establishes up and down loads, roll loads, lateral loads, longitudinal loads and torsional loads respectively by proper bridging, analysis of responding to coupling and the technical of stress concentration. |
