Study of Dynamic Birefringence and Strain Produced in Transparent Polymers by Mechanical Impact

Wilde, Anthony F.; Ricca, John J.; Lynch, F.

doi:10.21236/ad0630913

Cited by 1 publication

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These time relationships are shown schematically in Figure 13 Use of this crack initiation time then permitted a rough estimate of the magnitude of the incident longitudinal pulse at the back end of the specimen at the time of crack initiation. This was done by using unpublished strain gage data obtained during similar impacts on CR-39 strip specimens (1). The result produced with a 3/6-inch CR-39 anvil cemented to a CR-39 specimen in this previous work is shown in the strain gage record of Figure 14.…”

Section: Crack Initiation Time Estimatedmentioning

confidence: 99%

Photographic Study of Stress Wave Propagation and Crack Growth in a Transparent Plastic

Wilde¹,

Ricca²

1966

Self Cite

View full text Add to dashboard Cite

In order-to develop techniques for studying the transient behavior of plastic materials subjected to mechanical impact, a preliminary photographic investigation was undertaken with an electronic image converter camera system. Two types of events were recorded with CR-39 plastic serving as the specimen material: 1. Stress pulses, produced in the plastic by mechanical impaction, were studied by observation of the resulting fringe patterns. The pulse fronts were characterized in terms of shape and propagation velocity» An empirical equation was derived to express the decrease in slope of segments of the pulse front as it propagated through the specimen. 2. Propagating cracks, generated in the plastic by mechanical impact, were subjected to photographic analysis. Crack prorogation velocities and estimated crack initiation times were obtained. These served to yield;a rough estimate of the magnitude of the incident longituddnal pulse level at which crack initiation occurred. viii pa. ~»*l^-«

show abstract

Section: Crack Initiation Time Estimatedmentioning

confidence: 99%