拉伸试验机参数设定对铝合金试验结果的影响

Influence of setting parameters of tensile testing machine on test results of aluminum alloy

通过对拉伸试验机的不同参数设定(包括拉伸试验速率、弹性模量直线段的选择、断裂点检测的判定和引伸计的规格等)研究了其对铝合金拉伸试验结果的影响。实验结果表明,软件设定的试验速率增大,合金的强度增加,断后伸长率减小,弹性模量基本没变化;且随着试验速率的变化屈服强度比抗拉强度的变化更加明显,塑性大的合金对试验速度的敏感性大。弹性直线段的起始点和结束点的参数设定对合金的弹性模量、最大力塑性延伸率和引伸计反馈的断后伸长率有影响。不同方式的断裂检测点的判定同样对引伸计反馈的断后伸长率有影响,为了保证试验数据具有可比性,一般以手动测量的断后伸长率为试验对比数据;在切换不同引伸计时,必须设定正确的引伸计参数,否则将影响拉伸试验数据的真实性和准确性。

Through setting different parameters of the tensile testing machine,including the tensile test rate parameter,the selection parameter of the straight line segment of the elastic modulus,the determination parameter of the fracture point detection and the specification parameter of the extensometer,the influence on the tensile test results of aluminum alloy was studied.The test results show that with the increase of the test rate,the strength of the alloy increases,the elongation after fracture decreases,and the elastic modulus basically does not change,and the change of the yield strength with the test rate is more obvious than the change of the tensile strength,and the alloy with large plasticity is more sensitive to the test rate.The parameter setting of the starting point and ending point of the elastic straight line segment has an effect on the elastic modulus,the maximum plastic elongation and the elongation after fracture fed by the extensometer.The determination of different fracture detection points also has an impact on the post-fracture elongation feedback of the extensometer.In order to make the test data comparable,the hand-measured post-fracture elongation is generally used as the comparison data of the test.It is necessary to set the correct extensionmeter parameters when switching between different extensionmeter timing,otherwise the authenticity and accuracy of tensile test data will be affected.