# Determine the Young’s Module

Item no.: F13

##### Introduction

The Young Modulus, named after Thomas Young (1773 to 1829) who was an outstanding British polymath in material fields, is usually used to define the proportionality of normal stress and normal strain for metal material subjected to external force. Such proportionality constant only prevails within the working region below elastic limit i.e., transient distortion or deflection of material might be recovered after the external force is removed. It is, of course, far lower than ultimate limit accessed where the permanent strain or failure of material will occur. Thus using the Young Modulus to predict the validity of substance, especially in elastic behavior, seems to be inevitable prior to it being in engineering application. Also it could be treated as an effective manner for engineer to evaluate the safety factor of substance selected for public construction.

##### Objectives
1. Determine the Young’ Module by metal wire.
2. Determine the Young’ Module by deflection of a beam.
3. Determine the length and thickness by caliper gauge and micrometer
##### Experiment— Determine the Young’ Module by metal wire

To estimate the Young’s Module of material, tension method and beam- deflection method are usually introduced using the instrument of load cell, vernier calipers and scalar meter. Firstly in tension method, the measurement of wire -enlargement ration ΔL/L, caused by force F subjected to metal wire of one end fixed, might carried out, here radial displacement is assumed to be far smaller than the axial extension, i.e., only the shear stress and strain along the force component, in this subject, will be taken into account.

##### Experiment—Determine the Young’ Module by Deflection of a Beam

Secondly in beam-deflection method, the central deflection will be gradually augmented as the force F is enforced at. And Young’s modulus based on the ration of bending stress and bending strain, might be yielded below while the state of material still falls within the elastic region.

##### 實驗項目：
1. 測量金屬線的延長彈性係數
2. 利用彈性曲線方程式測定金屬棒的楊氏係數
##### 實驗器材：
1. 鋁製實驗平台 x1
2. 可變金屬線長度固定座 x1
3. 可變實驗金屬棒長度固定座 x1
4. 金屬片拉推桿 x1
5. 拉力感測器固定座 x1
6. 待測金屬線鋼線 x2（不同直徑），銅線 x1
7. 待測金屬片鋼片 x2（不同寬度），塑膠片 x1
8. 選購或自備品 – Datalogger電腦數據擷取器 x1、作用力感測器 x1