Experimental Mechanics

, Volume 16, Issue 9, pp 349–355 | Cite as

Shock-front loading method for studies in dynamic photoelasticity

Paper outlines a versatile method of applying a well-defined dynamic load to models for photoelastic stress studies
  • A. W. Miles
Article

Abstract

A versatile technique for applying a well-defined dynamic load to models for studies in dynamic photoelasticity is described. The method utilizes the shock front produced in a gas-dynamic shock tube to apply a load to models by direct normal impact. The principles and scope of the method are described and some examples of the dynamic stresses arising from shock-front impact on a low-modulus photoelastic model are presented and discussed. The method is suited to studies where simple variation and accurate determination of the load-cycle parameters, as well as precise reproducibility, are necessary. The method, in addition, permits close-field study of the initial response of materials to dynamic loading to be undertaken.

Keywords

Mechanical Engineer Fluid Dynamics Dynamic Load Shock Front Accurate Determination 

Symbols

c

shock-wave speed (m/s)

P

absolute pressure (kPa)

Pij

P i /P j where subscriptsi orj aren

n

1—refers to undisturbed region ahead of shock front

n

2—refers to region behind incident-shock front

n

5—refers to region behind reflected-shock front

Pr

(P 5 −P 1 )—reflected-shock pressure sensed by model (kPa)

Vs

velocity of incident-shock front (m/s)

γ=α+1/α−1 where α

ratio of specific heats (Cp/Cv) 1, 4 for air

ρ

density (kg/m3)

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Copyright information

© Society for Experimental Mechanics, Inc. 1976

Authors and Affiliations

  • A. W. Miles
    • 1
  1. 1.Department of Mechanical EngineeringUniversity of Cape TownRondebosch, Cape ProvinceSouth Africa

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