It is extremely difficult to predict the initiation time of cracking due to a large time spread in most cracking experiments. Thus, probabilistic models, such as the Weibull distribution, are usually employed to model the initiation time of cracking. Therefore, the parameters of the Weibull distribution are estimated from data collected from a cracking test. However, although the development of...

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...

iii Abstract: High manganese TWIP (TWinning Induced Plasticity) steels are particularly attractive for automotive applications because of their exceptional properties of strength combined with an excellent ductility. However, as austenitic steels, they appear to be sensitive to liquid zinc embrittlement during welding, the liquid zinc arising from the melted coating due to the high temperatures...

Theoretical models are developed for heat conduction and thermal expansion in a fiber-reinforced ceramic cross-ply laminate containing an array of parallel transverse matrix cracks. Two stages of the transverse matrix cracks are considered : Stage-I with tunnel cracks in the 90” plies aligned parallel to the fibers, and Stage-II with cracks extended across both the 90 and 0” plies with intact f...

Conventional shear-lag analyses of matrix cracking and debonding in uniaxial composites loaded in tension predict that the matrix stress varies only very slowly with position except near existing cracks. It therefore follows that the location of subsequent cracks is very sensitive to minor local variations in matrix strength, leading to significant statistical variation in crack spacing. This q...

Current article describes application of zeolites in fluid catalytic cracking (FCC). The use of several zeolitic additives for the production light olefins and reduction of pollutants is described. Application of zeolites as fluid catalytic cracking (FCC) catalysts and additives due to the presence of active acid sites in the zeolite framework  increase the formation of desired cracking product...

Modern business applications and scientific databases call for inherently dynamic data storage environments. Such environments are characterized by two challenging features: (a) they have little idle system time to devote on physical design; and (b) there is little, if any, a priori workload knowledge, while the query and data workload keeps changing dynamically. In such environments, tradition...

Abstract Combinations of temperature, stress and hot corrosion may cause environmentally-assisted cracking in precipitation-hardened Ni-base superalloys, which is little understood. This research aims to increase current understanding by investigating the effects mechanical on propagation rate during corrosion-fatigue testing CMSX-4, CM247LC DS IN6203DS. The parameters used tests included a hig...