A mathematical model and numerical estimation of setting stresses in polymer composites molded under hydrostatic pressure
✍ Scribed by A. M. Boriek; A. S. El-Bakry; C. D. Armeniades
- Publisher
- Springer
- Year
- 1992
- Tongue
- English
- Weight
- 917 KB
- Volume
- 26
- Category
- Article
- ISSN
- 0022-0833
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✦ Synopsis
The effect of compression molding (i.e. molding under hydrostatic pressure) on the magnitude and distribution of setting stresses in particle-reinforced polymer composites is investigated using the finite element method. Models based on fairly random arrangements of the reinforcing particles are used, with different particle size gradations, as well as different aggregate-to-resin ratios. An analytical expression of the maximum setting stresses in these composites is introduced. A non-linear constrained optimization technique is used to obtain the mathematical model parameters which aid in a reasonable numerical estimation of the maximum setting stresses in real systems. The numerical results show that externally applied hydrostatic pressure helps diminish some of the local setting stresses. However, this relief becomes insignificant at the interface between aggregate particles and the resin domains where local setting stresses are maximum. This indicates that the practice of compression molding does not have a significant effect in reducing local setting stresses in ordinary polymer concrete systems.
* The packing factor is equal to the total volume of the solid particles divided by the total volume of the composite.
* Large values of E is an indication that the radius of the trust region 6 is small and vice versa.