In general, it is required mechanical properties and strength tests to use the material in engineering applications. The material fringe values of photoelastic materials vary with the supplier, the batch of resin, temperature and age, it is necessary to calibrate each of sheet of photoelastic material at the time of the test. In this paper, we perform tensile tests and calibrations tests for photoelastic stress fringe constant in order to obtain the mechanical properties of materials and photoelastic material fringe constants of PMMA and PSM-1. From this tests, the tensile strength of PMMA and PSM-1 were 100.5 MPa and 71.5 MPa, respectively. Also, the measured material stress fringe constants of PMMA and PSM-1 were 13.33 N/mm and 6.91 N/mm, respectively.
In a photoelastic experiment, it is necessary to know the material stress fringe constant of the photoelastic specimen to determine the stresses from the measured isochromatic fringe orders. This type of compensator was proposed by the previous researchers. The recent image processing development of the stress pattern provide a means for making convenient compensator. The material stress fringe constant is determined using the distributions of isochromatic fringes in the wedge shaped plate under tensile load. The stress fringe constant measured with this method is applied to obtain the stress distribution along the central line on the tapered shank of the wedge-shaped plate. Photoelastic results using the measured material fringe constant are compared with FEM analysis. Two results are comparable, so it can be seen for the measured material fringe constant to be valid.
Many polymers exhibits sufficient birefringence to be used as photoelastic specimen material. Common polymers as polymethylmethacrylate (PMMA) are often used as photoelastic specimen. In a photoelastic experiment, it is necessary to know the material fringe constant of the photoelastic specimen to determine the stresses from the measured isochromatic fringe orders. The material stress fringe constant is determined using the simple tension specimen. The stress fringe constant measured with this method is applied to obtain the stress distribution in a tensile plate with a circular hole. Photoelastic results using the measured material fringe constant are compared with FEM analysis. Two results are comparable, so it can be seen for the measured material fringe constant to be valid.
CH 렌즈에 가한 웅력을 측정하기 위한 편광기는 광원-편광판-시료-편광판 -CCD컴퓨터로 구성하였고, 각 편광판의 단계별 광 파의 EJ, E2 의 성분올 분석하여, 주 웅 력차 01- σ2 와 무늬 차수 (n) 즐 유도하였다. 시료의 광 축은 주 응력 방향과 일치하 는 것으로부터 2 차원 모텔을 결정할 수 있다. 팡 파에 작용하쓴 이중 룹절성과 위상 지연은 주 웅력차(σ1-σ2) 에 비례하며, 최종 광 파의 세기는 sin2( il /2) 에 비례하고, il/2"nπ(n=O, 1, 2, ... )일 때 홉팡이 일어난다. 크기가 I! xW(40X20mm) 형태인 3.00D 렌즈의 외부 옹력의 크기에 따라 홉광 band가 이동함올 볼 수있고, 최대하증, slope, 최 대 하중 stress 값을 각각 23.99(Kgf), 43.73(Kgf/mm), O.076(Kgf/mm2 ) 값을 얻었다.