Dynamic Scattered Light Photoelasticity in Two-Dimensional Problems

1972 ◽  
Vol 39 (2) ◽  
pp. 606-607 ◽  
Author(s):  
J. H. Hemann ◽  
R. J. Becherer
Keyword(s):  
Wave Propagation ◽  
Rectangular Plate ◽  
Plane Stress ◽  
Scattered Light ◽  
Stress Wave Propagation ◽  
Two Dimensional ◽  
Normal Stresses ◽  
Explosive Load ◽  
Wave Propagation Problem ◽  
The Individual

The individual normal stresses in a two-dimensional plane-stress wave-propagation problem can be determined directly by using scattered light photoelasticity. The applicability of the method is shown by subjecting a rectangular plate to an explosive load.

The Effect of Plate Curvature on the Influence of Macroscale Geometric Voids in Controlling Stress Wave Propagation

2020 ◽  
Author(s):  
C. S. Florio
Keyword(s):  
Wave Propagation ◽  
Stress Wave ◽  
Plane Stress ◽  
Cylindrical Shells ◽  
Reaction Force ◽  
Stress Waves ◽  
Stress Wave Propagation ◽  
Axial Impact ◽  
Plate Curvature ◽  
Metal Plates

Abstract Much work has been done to create and understand means to control the propagation of acoustic and light waves through materials and structures. The ability to perform similar studies on the control of stress waves has implications not only for the development of capabilities to disrupt stress waves in order to limit their damage, but also to direct stress waves in order to tailor the behavior of a structure for a specific functional goal. Recent studies have demonstrated the use of voids and inclusions of varying size, geometry, arrangement, and composition in structures to attenuate impact forces or cloak stress waves in thin, flat, plane stress plates. However, many structures that may benefit from these wave modification methods are comprised of cylindrical shells. It is not currently known how well the techniques to control wave propagation and trends identified in plane stress plates can be applied to structures with cylindrical shells. Therefore, this study develops and uses computational modeling methods to examine the modification and control of stress waves induced by an axial impact load in metal plates of varying curvature through the inclusion of macroscale voids. Methods are developed and used in this work to study the response of metal plates of varying curvature with and without voids of different shapes and arrangement to axial impact loads. The response is quantified through the magnitude of the fixed end reaction force and through normal oscillations of discrete points along the length of the plate. Fast Fourier transformation and wavelet coherence techniques are used to understand both the time-averaged and time-dependent oscillation behavior. Correlations are drawn between plate curvature and void design on the control of the propagation of stress waves. The knowledge gained can help guide the understanding design of these stress wave modification features.

Plane Stress Wave Propagation in Solids

1970 ◽  
Vol 41 (1) ◽  
pp. 360-363 ◽  
Author(s):  
Richard Fowles ◽  
Roger F. Williams
Keyword(s):  
Wave Propagation ◽  
Stress Wave ◽  
Plane Stress ◽  
Stress Wave Propagation

A PHOTOELASTIC ANALYSIS OF STRESS WAVE PROPAGATION IN A LAYERED MODEL

Geophysics ◽  
1966 ◽  
Vol 31 (5) ◽  
pp. 881-899 ◽  
Author(s):  
W. F. Riley ◽  
J. W. Dally
Keyword(s):  
Wave Propagation ◽  
Dynamic State ◽  
Lead Azide ◽  
Stress Wave Propagation ◽  
Principal Stresses ◽  
Individual Values ◽  
Isochromatic Fringe ◽  
Fringe Patterns ◽  
The Individual ◽  
Explosive Detonation

Dynamic photoelasticity was used to study some fundamental aspects of wave propagation in layered media and to obtain information on the dynamic state of stress associated with the various waves generated by a point source explosion. Columbia Resin CR‐39 and aluminum were used to obtain a model with an acoustical impedance‐mismatch between layers of 6 to 1. A Cranz‐Schardin multiple spark camera, operating at approximately 200,000 frames per second, was used to record the dynamic isochromatic fringe patterns associated with the propagating stress waves. Small charges of lead azide were used to explosively load the models. Six different wave types were clearly identified. In the region near the explosive detonation, the predominant waves were the incident [Formula: see text] wave and the reflected [Formula: see text] waves from the interface and the free boundary. In regions away from the explosive detonation the headwaves ([Formula: see text], [Formula: see text], and [Formula: see text]) dominate since their rate of attenuation is much lower than the rate associated with the incident dilatational or the reflected shear waves. The data obtained in the form of isochromatic fringe patterns were converted to individual values of the principal stresses in several instances. The methods developed for this separation are applicable whenever the dilatational or distortional waves occur alone. The separation method requires no auxiliary data other than the isochromatic fringe orders and yields dynamic displacement data in addition to the individual values of the principal stresses.

Sign in / Sign up

Export Citation Format

Share Document