DeHoff P H, Anusavice K J
J Dent Res. 1985 Nov;64(11):1337-44. doi: 10.1177/00220345850640111801.
An analytical model has been developed to calculate residual stresses and curvature changes due to thermal contraction differences in metal-porcelain strips consisting of any number (n) of component materials. This model was also used to analyze transient and residual stresses due to solidification of a semicircular arch casting. Results obtained from this model were in close agreement with those obtained from finite element calculations for the cases studied. Some experimental evidence exists to suggest that thermal contraction coefficients of certain body porcelains progressively increase with the number of firing cycles. Therefore, a parametric study was conducted to determine the effects of variations in the thermal contraction coefficient of each porcelain layer on residual stresses and gap changes produced in porcelainized semicircular arch specimens. Based on the analytical model developed in this study, we found that calculated residual stresses near interfacial areas of adjacent layers of porcelain are most sensitive to variations in thermal contraction coefficients of the material layers.
已开发出一种分析模型，用于计算由任意数量（n）的组成材料构成的金属烤瓷条因热收缩差异而产生的残余应力和曲率变化。该模型还用于分析半圆形牙弓铸件凝固过程中的瞬态应力和残余应力。对于所研究的案例，该模型得到的结果与有限元计算结果非常吻合。有一些实验证据表明，某些体瓷的热收缩系数会随着烧制循环次数的增加而逐渐增大。因此，进行了一项参数研究，以确定各瓷层热收缩系数的变化对烤瓷半圆形牙弓试件中产生的残余应力和间隙变化的影响。基于本研究开发的分析模型，我们发现，相邻瓷层界面区域附近计算得到的残余应力对材料层热收缩系数的变化最为敏感。
