Stresses compaction/residual

Regardless of matrix or fiber materials, the key process variables for filament winding are temperature, compaction pressure/fiber tension, and laydown rate. Typical measures of final cylinder quality include degree of cure/crystallinity, void volume fraction, fiber volume fraction, and residual stresses and strains. 

A major challenge is the densification of the graded powder compacts. The processing of FGM materials by powder metallurgy methods often faced undesirable excessive bending or warping of the component after sintering (Miyamoto et al., 1999). Due to excessive thermal residual stresses, cracks and other defects may often be observed in the final FGM component unless properly manufactured. 

Determination of the stress distributions within the powder compact, including residual stresses... 

One of the objective of this research is to fabricate diamond- gradually dispersed cermets by the combination technique of SHS for short time processing and following dynamic compaction for densification. The other is to support for the fabrication by the calculation of residual stress based on graded structure of diamond in the matrix. 

Key words autoclave processing, process modelling, flow, compaction, heat transfer, cure, dimensional control, residual stresses, cure cycle. 

After compaction of the fiber reinforcement network is completed and the matrix melt becomes a solid after cooling down (achieving consolidation), the elastic energy of the fiber reinforcement network is stored in the composite in the form of residual stresses. When the consolidated composite undergoes a reheating operation and its matrix commences to remelt, the elastic energy stored in the fiber reinforcement network tends to release, which is referred to as decompaction of fiber reinforcement. In this way, the decompaction of the fiber reinforcement network, denoted by should be proportional iop, , namely. 

Fig 3(b) shows the factor effects on non-weld strength. Here, melt temperature is the most important factor. The increase of melt temperature causes the decrease of the strength for the reason of the thermal residual stress increasing. The increases of holding pressure and holding pressure time cause the compact construct of the part, and thereby the increase of the strength. 

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