Impact Test Solid Mechanics An impact test is a dynamic test conducted on a selected specimen which is usually notched. The specimen is struck and broken by a single blow in a specially designed machine. This demo illustrates the experiment setup, procedure and the energy absorbed in an impact test.
Impact Test Solid Mechanics Impact Test Test-specimenPendulum Machine Aim: To measure the toughness, or energy absorption capacity of the materials. Notch
Impact Test Solid Mechanics Test Specimen – Support Conditions Charpy Test Setup Notch Specimen Point of Impact Specimen Simple beam support 44m
Impact Test Solid Mechanics Notch Izod Test Setup Cantilever beam support Test Specimen – Support Conditions
Impact Test Solid Mechanics Equations Initial Energy (E i ) = mga = Wa Impact Velocity = v = (2ga) Energy after rupture (E r ) = mbg = Wb Energy absorbed by the specimen (Eab) = E i – E r = mga - mgb 1/2
Impact Test Solid Mechanics Charpy Experiment Simulation Drag the specimen to the support and click hammer. Specimen Simple beam support Hammer 1.Load the Specimen. 2.Release the Pendulum.
Impact Test Solid Mechanics 1.Load the Specimen. 2.Release the Pendulum. Click the Quiz button. 150 Charpy Experiment Simulation 0 Indicate P.E = 300J Energy Absorbed = 120J
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Impact Test Solid Mechanics Results of the Charpy Impact test and the Izod impact test cannot be compared can be compared if the specimens have the same dimensions should be used in tandem to estimate the toughness of the material can be compared if the pendulum / hammer has the same weight
Impact Test Solid Mechanics Results of an impact test can be used directly in design equations for components can be used in design equations for components only after empirical correlation has been obtained can be used in design equations after adjusting for temperature difference only cannot be used for design calculations
Impact Test Solid Mechanics Impact tests are independent of specimen size are independent of notch size are dependent on specimen size are dependent on notch size
Impact Test Solid Mechanics The temperature of the specimen does not affect the results of the test is directly proportional to the measured toughness is inversely proportional to the measured toughness affects the measured toughness differently for different materials
Impact Test Solid Mechanics Results of the impact test can be used directly to estimate yield strength cannot be used directly to estimate yield strength can be used to estimate yield strength based on empirical correlations can be used to estimate yield strength based on fundamental relationships