Presentation On

Universal Testing Machine

M Waqas Mushtaq MME-12-11 Muhammad Zubair MME-12-29 M. Faisal Maqsood MME-12-20 Muhammad Ahmad MME-12-14 Gulfam Hussain MME-12-30 Arif Ali MME-12-01

Group No 1

Mechanics Of materials: Mechanics of materials is a branch of mechanics that develops relationships between the external loads applied to a deformable body and the intensity of internal forces acting within the body as well as the deformations of the body. Stress Strain

Introduction

Stress Strain Diagram

Proportional limit

Elastic limit Yield Point Yield Strength Necking point Rupture Point

Necking & Rupture

Universal Testing Machine

The results from the test are commonly used to select a material for an application, for quality control, and to predict how a material will react under other types of forces. Properties that are directly measured via a tensile test are ultimate tensile strength, maximum elongation and reduction in area. From these measurements the following properties can also be determined: Young's modulus, yield strength, and strain-hardening characteristics.

Tensile Test Compressive Test Tortion Test Shear Bending

Test Function

COMPONENTS

Load cell Cross head Output

device Test fixtures

(jaws) Extensomete

r Columns

TYPES

Mechanical The electromechanical machine

uses an electric motor, gear reduction system and one, two or four screws to move the crosshead up or down

. A range of crosshead speeds can be achieved by changing the speed of the motor.

A microprocessor based closed-loop servo system can be Implemented to accurately control the speed of the crosshead.

Hydraulic A hydraulic testing machine uses

either a single- or dual-acting piston to move the crosshead up or down.

In a manually operated machine, the operator adjusts a needle valve to control the rate of loading. In a closed-loop hydraulic servo system, the needle valve is replaced by an electrically operated servo-valve for precise control.

In general, the electromechanical machine is capable of a wide range of test speeds and long crosshead displacements, whereas the hydraulic machine is a cost-effective solution for generating high forces.

TYPES

Digitally operated Universal Testing Machine

Computer operated Universal Testing Machine

Single Column Universal Testing Machines

Double / Dual Column Universal Testing Machines

Four Column Universal Testing Machines

It works on the principle of elongation and deformation.

In UTM Tensile, Compressive and Shear Forces are acting.

Working Principle

Working Procedure Compression Test

In compression test the specimen is gripped in machine jaws and load is applied through a screw gear mechanism by a movable crosshead jaw when we apply load our specimen is compressed under load and its compressive strength shows on screen by graph.

In tensile test the specimen is gripped in machine jaws and load is applied through a screw gear mechanism by a movable crosshead jaw when we apply load our specimen is elongated under load and stress strain graph is shown on screen.

Tensile Test

TENSILE TEST

Step 1: Original shape and size of the specimen with no load.

Step 2: Specimen undergoing uniform elongation.

Step 3: Point of maximum load and ultimate tensile strength.

Step 4: The onset of necking (plastic instability).

Step 5: Specimen fractures. Step 6: Final length.