Creep Dynamic fracture

It can be said that the design of a product involves analytical, empirical, and/or experimental techniques to predict and thus control mechanical stresses. Strength is the ability of a material to bear both static (sustained) and dynamic (time-varying) loads without significant permanent deformation. Many non-ferrous materials suffer permanent deformation under sustained loads (creep). Ductile materials withstand dynamic loads better than brittle materials that may fracture under sudden load application. As reviewed, materials such as RPs can exhibit changes in material properties over a certain temperature range encountered by a product. 

Material Brazed Specimens Creep Cyclic Density Dynamic Elasticity Fracture Hardness Interrupted Material... 

Fig. 8. Vibration-induced creep fracture, (a) Radially propagating dynamic fatigue fracture inside the material and (b) dynamic creep fracture in PS samples.

Three processes can contribute the polymer fracture, by fatigue, namely - 1) thermal softening 2) flowing or accelerated creep and 3) initiation and propagation of fatigue s cracks [834], The parameters of dynamical fatigue have been defined by E.H. Andrews, [831], and are the following ... 

Work by Schapery, Saxena, Wilhams, and others details the analysis of cracks in creeping, strain rate dependent materials, and provides a predictive basis for the apparently brittle nature of FCP in UHMWPE [43-48]. Particularly usefid are the models developed by Schapery and Wilhams, which directly link the intrinsic, constitutive viscoelastic relaxation behavior of the material to the advance of a stable crack tip [46,48]. The power of these models is the predictive nature of the mechanics in relating ECP dynamics to the material s viscoelastic behavior that is eashy measured in a simple one-dimensional creep test The elementary consequences of the models result in the static mode fatigue crack propagation behavior that is observed in UHMWPE, and thus potentially provide a first-principles explanation of the fatigue and fracture behavior by the material. 

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