Universal testing machines

1. Presentation On Universal Testing Machine

2. 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

3. 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

4. Stress Strain Diagram Proportional limit Elastic limit Yield Point Yield Strength Necking point Rupture Point

5. Necking & Rupture

6. 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.

7. Tensile Test Compressive Test Tortion Test Shear Bending Test Function

8. COMPONENTS Load cell Cross head Output device Test fixtures (jaws ) Extensometer Columns

9. TYPES M echanical 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. H ydraulic 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.

10. 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

11. It works on the principle of elongation and deformation . In UTM Tensile, Compressive and Shear Forces are acting. Working Principle

12. 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.

13. 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

14. 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.