Impact fracture

Hobbs, S. Y. and Pratt, C. F., The effect of skin-core morphology on the impact fracture of polybutylene terephthalate, J. Appl. Polym. Sci., 19, 1701-1722 (1975). 

Fig. 7.5. (a) Transverse impact fracture toughness and (b) fiber pull-out length versus testing temperature for carbon fiber-epoxy matrix composites with and without PVAL coatings on fibers. After Kim and... 

Fig. 7.8. (a) Normalized impact fracture toughness and (b) interlaminar shear strength (ILSS) of carbon fiber-epoxy matrix composites as a function of glycidyl acrylate/methyl acrylate (GA/MA) interlayer... 

Fig, 7.16, Impact fracture toughness (O) and interlaminar shear strength (ILSS, ) of carbon fiber-epoxy matrix composites with varying number of nylon sheets as delamination promoters. After Havre (1977). 

An unstable crack is primarily driven by the elastic energy already stored in the specimen (and not so much by the energy introduced into the specimen by the continued deformation). A pertinent experiment was carried out by Stalder [30], who investigated the impact fracture of PMMA using an instrumented hammer nose and standard notched Charpy specimens with sprayed-on graphite strain gages. With this double-instrumentation technique... 

Brief History. B.W., a 75-year-old woman, fell at home and experienced a sudden sharp pain in her left hip. She was unable to walk and was taken to a nearby hospital where x-ray examination showed an impacted fracture of the left hip. The patient was alert and oriented at the time of admission. She had a history of arteriosclerotic cardiovascular disease and diabetes mellitus, but her medical condition was stable. The patient was relatively obese, and a considerable amount of osteoarthritis was present in both hips. Two days after admission, a total hip arthroplasty was performed under general anesthesia. Meperidine (Demerol) was given intramuscularly as a preoperative sedative. General anesthesia was induced by intravenous administration of thiopental (Pentothal) and sustained by inhalation of halothane (Fluothane). The surgery was completed successfully, and physical therapy was initiated at the patient s bedside on the subsequent day. 

Results. AES analysis of impact fracture surfaces on nickel showed considerable spread in sulfur composition at grain boundaries as shown in Fig. 2. The composition varied from approximately 0.04 to 0.20 monolayers on the sample heated to 1100°C for one hour and 0.15 to 0.25 monolayers on a sample that had received additional heating at 600°C for 240 hours. The additional heat treatment shifted the average grain boundary composition by nearly 0.1 monolayer of coverage. 

Grein C, Beguelin P, Plummer CJG, Kausch H-H, T6z6 L, Germain Y (2000) Influence of the morphology on the impact fracture behaviour of iPP/EPR blends. In Williams JG, Pavan A (eds) Fracture of polymers, composites and adhesives, ESIS Publication 27. Elsevier, Oxford... 

Although the processing variables appear to have correlations with morphology, results of impact tests fail to produce a definitive description of the morphological response to impact. However, this problem is shown to be substantially eliminated through the use of instrumented impact testing (17). Such tests measure the time dependence of the impact load borne by the sample and indicate that impact fracture is a... 

Dynamic and Impact Fractures of Ceramic Composites at Elevated Temperature... 

Figure 1. Impact fracture surface of polymerized acrylic dispersion, no dimethacrylate, SEM 17.5X...

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