基于拉伸法测量金属丝杨氏模量的实验研究

Experiment Study on the Measuring Young’s Modulus by Stretching

金属丝杨氏模量测定是大学物理实验中重要实验之一,该实验综合训练学生基本测量、数据处理、测量技巧等物理实验技能。本文对原有教学内容进行了一定的扩展,从方法上,提出附加参照尺方法测量镜尺间距和金属丝长度这两个较难准确测量的长度量,提高测量精度;从内容上,通过增、减砝码时相同应力对应不同应变的特点,拓展材料弹性滞后性能的研究内容;从数据处理方面,借助Origin软件分别采用最小二乘法和逐差法对数据进行处理,得到的杨氏模量数值分别为1.87520×10^11 Pa和1.87918×10^11 Pa,两者的相对误差仅为2%。

The determination of Young’s modulus of wire is one of the important experiments in college physics experiment.This experiment comprehensively trains students’basic physical experiment skills,such as measurement,data processing and measurement skills.In this paper,the teaching content has been expanded.For the aspect of the method,the reference ruler is proposed to measure the distance between mirror rulers and the length of wire,which is difficult to accurately measure,so as to improve the measuring accuracy.For the aspect of the content,the research contents of elastic hysteresis property of materials are expanded by the characteristics of stress corresponding to strain when adding or subtracting weights;In terms of data processing,the least square method and item-by-item difference method are adopted to process the data,the young’s modulus values obtained are 1.88454×10^11 Pa and 1.88959×10^11 Pa,respectively.The relative error between them is only 2%.