• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.1
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• pp.8-18
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• 1988

In the composite structures or the concrete structures, to analyze stress concentration factor, stress distributions and fracture mechanics of them under forces by photoelastic experiment, it is natural that to develope photoelastic model material for them is surely necessary. Thus, the orthotropic photoelastic model material for the transparent type photoelastic device was developed in the paper, it is called Copper Fiber Epoxy Composite and abbreviated as E.F.E.C. It was found that C.F.E.C. developed in this paper was satisfied with the properties of photoelastic model material that the photoelastic model material should have and that C.F.E.C. had completely properties of composite material. It is thought that C.F.E.C. can be applied to both medical engineering for modeling biological tissue and to the aerospace industry as orthotropic photoelastic material.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.8
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• pp.1876-1888
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• 1995

In this paper, glass surface-mat reinforced epoxy(G.S.R.E.) is developed, It is assured that the material(G.S.R.E.) can be used as photoelastic model material and it satisfy with the required properties of photoelastic model material. Therefore, the material can be used as model material of transparent photoelastic experiment when we analyze the stress distributions of transversely isotropic material by photoelastic experiment. When we use G.S.R.E. as photoelastic experiment model material, we had better use the G.S.R.E. which fiber volume ratio is less than 0.7% in the high temperature(stress freezing method) and than 1.74% in the room temperature. Relationships between stress fringe value and elastic modulus in transversely isotropic material are developed in this paper, it is assured by experiment that they are established in the room temperature or in the high temperature. Therefore we can obtain stress fringe value or elastic modulus from the relationships between stress fringe value and elastic modulus.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.4
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• pp.723-736
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• 1992

Most degeneating diseases and back pains in the orthopaedic disease are originated from the unbalance of stress distribution in the low-lumbar spine. Therefore the stress analysis of lowerback is indispensible to the clinical diagnosis for the developing reason and the developing process of diseases. Therefore the same model materials as following are eveloped to analyze the stress distributions of lower-back by photoelastic experiment. The verterbral body and the process are molded from epoxy resin(the weight ratio of Araldite and hardner is 10 to 3), models are geometrically identical to them in vivo respectively and the ratio of their elastic modulus to that of model material is 1 to 10. It is assured that KE-1300 Silicon(E=0.8MPa), TSE-3562 Silicon(0.5MPa) and the composite silicon(3MPa) (the weight ratio of KE-1300 silicon and Jioreal : 10 to 4) are respectively effective as the model materials of ligament, musles and intervertevral disc which is essential to the movement of low-lumbar spine. All the elements associated with the movement of the low-lumbar spine are molded through the molding method developed in this research and assembled with the angles between the verterbra and the disc in the normal human lumbosacral spine. The stress distributions of the assembled model are analyzed by photoelastic experiment. It is certified by comparing the results of photoelastic experimebt with the clinical situations that the loading dveice and the loading conceptions used in this paper are effective.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.3
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• pp.624-634
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• 1998

The photoelastic model material with shape memory effect and the molding processes for the material are developed in this research. The matrix and fiber of the photoelastic model material developed in this research are epoxy resin (Araldite to hardner 10 to 3 (weight ratio)) and wire of $Ti_50-Ni_50$ shape memory alloy, respectively. It is called Ti50-Ni50 Shape Memory Alloy Fiber Epoxy Composite $(Ti_50-Ni_50SMA-FEC).$ Ti50-Ni50 SMA-FEC is satisfied with the requirements of the photoelastic model material and can be used as a photoelastic model material. The maximum recovering strain of $Ti_50-Ni_50$SMA-FEC is occurred at $80^{\circ}C$ in any prestrain of $Ti_50-Ni_50$ shape memory alloy fiber and in any fiber volume ratio. Recovering strain(force) is increased with the increment of the prestrain and the fiber volume ratio. The best prestrain of $Ti_50-Ni_50$SMA-FEC is 5% for the recovering force among 1%, 3%, 5%.