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
袁康博 1杨建辉 2李泊立 2赵思晗 2吴名疆 2杨松淼 2郭伟国2
作者信息
- 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
- 折叠
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.
Abstract
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 single-pulse 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 perform-ance 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 pa-per 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 Hop-kinson bar is controllable and measurable,which is beneficial to realizing constant-amplitude cyclic load-ing.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 meth-od because it can achieve constant amplitude loading and obtain comprehensive test data.Finally,a con-stant-amplitude dynamic shear fatigue test method is developed using the three-wave technique.Impact fa-tigue performance tests are carried out on the TC4 titanium alloy.The test loading frequency is 0.1 Hz,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,the impact fatigue loading in other loading modes(such as tension,compression,etc.)can also be real-ized.
关键词
冲击疲劳/Hopkinson杆/应力波/恒幅/动态试验技术Key words
impact fatigue/Hopkinson bar/stress wave/constant amplitude/dynamic test techniques引用本文复制引用
基金项目
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)
国家自然科学基金项目(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)
出版年
2024
NETL
NSTL
万方数据