Rate-independent energy dissipation associated with high-strain high-stress behavior of the material is considered. This rate-independent energy dissipation is associated with damage and relative motion inside the fiber-matrix material system. Simple mechanical models for energy dissipation were presented to facilitate the understanding of the phenomena. Three mechanisms for internal energy dis...

Kevlar is a type of aramid fibers which is characterized by high strength to low weight ratio. This material is widely used in bulletproof vests and helmets, in which it creates a barrier to projectiles to protect specific objectives, laminated tubes and pressure vessels, etc. In this study the ballistic behavior of Kevlar /epoxy composite and Kevlar fabric is investigated. The results showed t...

Excellent exposures on wave-cut platforms display along the northeastern Taiwan coast a thick Oligocene succession that suffered low-grade metamorphism. The strata show anisotropic ductile-brittle deformation associated with the Late Cenozoic Taiwan mountain building event. Paleomagnetic analyses suggest probable contraction-induced remagnetization of remanent magnetization, taking place before...

Background and Objectives: Kefiran (Kef) is a water-soluble polysaccharide that can form transparent film however, it is brittle. Therefore, in order to improve the mechanical properties of kefiran film, a mixture with other polymers can be offered. The expansion of mixed systems can propose kefiran and polyvinyl alcohol (PVOH) as a new composite film. Materials and Methods: Solutions of 20 gr...

II. PHENOMENOLOGY OF PLASTIC DEFORMATION When a body is exposed to external stress, it responds either by moving, or by deforming. Depending on the magnitude of the stresses applied, there are two types of possible deformations 1) For low stresses, the strain is proportional to the applied stress (Hooke’s law) and comes back to its original position when the stress is removed. This is called el...

The structure and mechanical properties of crystalline materials of three boron difluoride dibenzoylmethane (BF2dbm) derivatives were investigated to examine the correlation, if any, among mechanochromic luminescence (ML) behaviour, solid-state structure, and the mechanical behaviour of single crystals. Qualitative mechanical deformation tests show that the crystals of BF2dbm( (t) Bu)2 can be b...

Molecular dynamics simulations were performed to demonstrate the synergistic effects of the extrinsic size (nanowire length) and intrinsic size (twin boundary spacing) on the failure manner, yield strength, ductility and deformation mechanism of the twinned nanowires containing high density coherent twin boundaries CTBs paralleled to the nanowires’ axis. The twinned nanowires show an intense ex...

The introduction of rubbery particles can be applied to enhance shear yielding and, consequently, the toughness of brittle amorphous polymers. The critical transition in these polymers from crazing to shear yielding requires a submicrometeror even nanometer-sized rubbery phase. These can be obtained via coalescence suppression in processes involving chemically induced phase separation but are a...

Collagen is a protein material with superior mechanical properties. It consists of collagen fibrils composed of a staggered array of ultra-long tropocollagen (TC) molecules. Theoretical and molecular modeling suggests that this natural design of collagen fibrils maximizes the strength and provides large energy dissipation during deformation, thus creating a tough and robust material. We find th...