A new specimen for growing dynamic cracks along a well defined path using stress wave loading

Experimental and numerical study of the interaction between dynamically loaded cracks and pre-existing flaws in edge loaded PMMA specimens

“…al. [37], the specimen was notched with a blunt notch and no pre-crack was introduced, similar published experiments on the dynamic fracture of PMMA have previously used the same approach [40,41]. In the experiments presented here, a sharp pre-crack was introduced to the already notched specimens by inserting a razor blade into the notch (0.7mm wide) and lightly impacting it, resulting in sharp cracks of approximately 0.4 ± 0.1 mm in length.…”

“…al. [37] for the dynamic fracture of brittle materials (Figure 1). The main criteria for choosing this geometry was the ease of specimen alignment which will allow us to study the crack-holes interaction in a rather consistent manner by minimizing errors arising from the activation of a mixed-mode scenario.…”

“…The main criteria for choosing this geometry was the ease of specimen alignment which will allow us to study the crack-holes interaction in a rather consistent manner by minimizing errors arising from the activation of a mixed-mode scenario. Furthermore, it was shown in [37] that the resulting crack path is very predictable which allows us to place the holes along a known path. In Chen et.…”

“…Following [37], the specimens were loaded using a Hopkinson bar in the 1-bar configuration (19.7 mm diameter, C300 Maraging steel bar). A schematic of the loading apparatus is shown in Figure 4.…”

“…The present study is a detailed analysis of the crack-hole interactions for dynamically loaded PMMA fracture specimens. A Hopkinson bar apparatus is used to facilitate crack growth using reverse tapered double cantilever beam specimens [37]. Taking advantage of the well-predicted crack path in the unperturbed configuration, cylindrical holes are pre-machined into the crack path and the crack-hole interaction is studied using high-speed photography (up to 2x10 6 fps and 924x768 pixels).…”