基于Hopkinson杆的恒幅冲击疲劳试验方法研究  

Research on Constant-Amplitude Impact Fatigue Test Method Based on Hopkinson Bar

作　　者：袁康博 杨建辉 李泊立 赵思晗 吴名疆 杨松淼 郭伟国[2] Kangbo Yuan;Jianhui Yang;Boli Li;Sihan Zhao;Mingjiang Wu;Songmiao Yang;Weiguo Guo(School of Mechanics,Civil Engineering and Architecture,Northwestern Polytechnical University,Xi’an,710129;School of Aeronautics,Northwestern Polytechnical University,Xi’an,710072)

机构地区：[1]西北工业大学力学与土木建筑学院,西安710129 [2]西北工业大学航空学院,西安710072

出　　处：《固体力学学报》2024年第1期1-15,共15页Chinese Journal of Solid Mechanics

基　　金：中央高校基本科研业务费专项资金(2022ZYGXZR057);国家自然科学基金项目(12072287,12202149);中国博士后科学基金(2022M711198);广州市基础研究计划与应用项目(2023A04J1564)资助.

摘　　要：在航空、航天、武器和能源等领域的结构件经常会受到小载荷(小能量)的重复冲击,不同于大能量的单次冲断和常规准静态疲劳,这种载荷形式被称为冲击疲劳.冲击疲劳性能的评估需要依赖科学有效的冲击疲劳试验结果.多年来,受到基于能量法的冲击疲劳试验方法的限制,冲击疲劳试验结果在结构设计和性能评估方面的工业应用十分有限.因此,本文首先基于对冲击疲劳试验方法的发展历程的简要回顾,肯定了基于Hopkinson杆原理的应力波法的优越性,明确了冲击疲劳试验中普遍存在的非恒幅加载的问题.同时,提出了几种基于Hopkinson杆原理的冲击疲劳加载技术,并通过试验验证技术的可行性,重点关注是否存在二次加载引起的非恒幅加载问题.最后,采用经典的分离式Hopkinson压杆技术开发了一套可实现恒幅加载的动态剪切疲劳试验方法,实现了对TC4钛合金的冲击疲劳性能测试,从而验证了新方法的有效性和可行性.Structural components in the fields of aviation,aerospace,weapons,and energy are often subjected to repeated impacts of small loads(or low energy).This type of load is different from the singlepulse impact of high energy and the conventional low-strain-rate fatigue,which is called impact fatigue.Because the energy-based impact fatigue test methods can only detect the relation between impact energy and fatigue life,the industrial application of impact fatigue test results in structural design and performance evaluation has been limited.Therefore,this paper focuses on exploring a new impact fatigue loading method.First,based on a brief review of the development of existing impact fatigue test methods,this paper affirms the superiority of the stress wave method based on the Hopkinson bar principle,and raises the problem of non-constant amplitude loading in impact fatigue tests.The waveform generated by the Hopkinson bar is controllable and measurable,which is beneficial to realizing constant-amplitude cyclic loading.Then,three impact fatigue loading techniques(namely the one-wave,two-wave,and three-wave techniques)based on the Hopkinson bar are proposed.The feasibility of these methods is verified through experiments,focusing on studying whether there is a non-constant amplitude loading problem caused by secondary loading.The three-wave technique is found to be the most effective impact fatigue loading method because it can achieve constant amplitude loading and obtain comprehensive test data.Finally,a constant-amplitude dynamic shear fatigue test method is developed using the three-wave technique.Impact fatigue performance tests are carried out on the TC4titanium alloy.The test loading frequency is 0.1Hz,and the test strain rate ranges from 6800/s to 8400/s.It is proved that this method can realize dynamic shear fatigue testing of metal materials at the strain rate level of 103/s.This study provides a new idea for the constant-amplitude impact fatigue test.By changing the forms of the specimen and the loading bars,

关 键 词：冲击疲劳 HOPKINSON杆 应力波 恒幅 动态试验技术 

分 类 号：O346.2[理学—固体力学]