A finite element analysis was conducted to determine the effect of moisture diffusion and hygroscopic swelling in rice. A parallel simple stochastic modeling was performed to predict the number of grains cracked as a result of moisture absorption and hygroscopic swelling. Rice grains were soaked in thermally (25C) controlled water and then tested for compressive stress. The destructive compress...

In this paper, comparisons of damage evolution between 2D C/SiC and SiC/SiC ceramic-matrix composites (CMCs) under tension-tension cyclic fatigue loading at room and elevated temperatures have been investigated. Fatigue hysteresis loops models considering multiple matrix cracking modes in 2D CMCs have been developed based on the damage mechanism of fiber sliding relative to the matrix in the in...

Brittle materials propagate opening cracks under tension. When stress increases beyond a critical magnitude, then quasistatic crack propagation becomes unstable. In the presence of several precracks, a brittle material always propagates only the weakest crack, leading to catastrophic failure. Here, we show that all these features of brittle fracture are fundamentally modified when the material ...

Micro-cracking in polycrystalline Silicon is a serious concern for the durability of photovoltaic (PV) modules due to the resulting electrical power-loss. In this contribution, a thermo-mechanical cohesive zone model is proposed to predict the evolution of micro-cracks under the action of mechanical and thermal loads. The classical nonlinear cohesive zone approach, used in fracture mechanics to...

To simulate more realistically the effects of strains and stresses on the reliability of portable electronic products, lead-free test assemblies were thermally cycled (−45°C/+125°C, 15-min. dwell time, 750 cycles) or isothermally annealed (125°C, 500 h) before the standard drop test. The average number of drops to failure increased when the thermal cycling was performed before the drop test (1,...

Thermal jet rock breaking technology refers to the use of high temperature medium such as supercritical water for a rapid local heating rocks break rocks. Because low thermal conductivity matrix, stress will only form on surface. When exceeds strength rock, micro-cracks appear in and continue expand, resulting cracking surface, which cause surface fall off from body rock. Based thermal-solid co...

This study addresses the problem of thermal stress development in bulky specimens during cryopreservation via vitrification (vitreous means glassy in Latin). While this study is a part of an ongoing effort to associate the developing mechanical stress with the relevant physical properties of the cryopreserved media and to its the thermal history, the current paper focuses exclusively on the rol...

In this paper, the comparison of cyclic hysteresis behavior between cross-ply C/SiC and SiC/SiC ceramic-matrix composites (CMCs) has been investigated. The interface slip between fibers and the matrix existed in the matrix cracking mode 3 and mode 5, in which matrix cracking and interface debonding occurred in the 0° plies are considered as the major reason for hysteresis loops of cross-ply CMC...

Carbon fiber-reinforced plastics (CFRP) laminate structures manufactured using prepregs usually contain fiber discontinuities that result from the prepreg cutting for design and cost-efficiency. In this study, sampling moiré method was used to measure microscopic strain of unidirectional CFRP laminates with investigate deformation behavior causes damage. addition distributions before after crac...

ANALYTICAL AND EXPERIMENTAL STUDY OF INVESTMENT CASTING WITH LASER STEREOLITHOGRAPHY MODELS by Wen-Long Yao This dissertation presents an analytical and experimental investigation of ceramic shell cracking during the burnout process in investment casting with internally webbed laser stereolithography (SLA) patterns. Included in the consideration are the cracking temperature of the ceramic shell...