Thermal Stresses at the Edge of a Bimetallic Thermostat

Abstract

The plane stress problem of a semi-infinite, bimetallic thermostat subjected to uniform heating or cooling is treated with the theory of elasticity. Solutions to this problem are expressed as the sum of a basic solution for a bimetallic strip of infinite length and a series of complementary solutions. Interlayer peeling stresses at the free edge of the bimetallic thermostat are shown to be singular or nonsingular (but still higher than the nominal values) depending upon whether the combination of the two Dundurs’ bimaterial constants, α (α−2β), are greater or less than zero. In an example problem, current solutions agree well with finite element results while results predicted by a modified beam theory show a large deviation from the other two solutions near the free edge. Boundary layer effects near the free edges of a bimetallic thermostat are also discussed.

Stress intensity factors for a crack in planar disking

“…Kuo [10] obtained an exact solution for an infinitely long bimetallic strip under similar conditions. Kuo's problem is not unlike the problem being considered here.…”

Fatigue Damage Evaluation for Microelectronic Components Subjected to Vibration

“…The smaller the element size, the higher the resulting strains. This finite element mesh size dependency is primarily due to the stress/strain singularity at the edge of a bimaterial (Kuo, 1990: Kuo et al, 1997Yin, 1992Yin, , 1993. Therefore, to minimize the mesh dependence problem, a volume-weighted average method (Kuo et al, 1997) is used to compute an average effective strain over all the elements in the critical layer:…”

Predicted thermal stresses in a bow-free adhesively bonded assembly for photonic packaging applications

“…These assemblies are typically manufactured at an elevated (curing) temperature and are subsequently cooled down to a low (room, operating, testing) temperature. Because of the dissimilar materials, such assemblies experience, at low temperature conditions, thermally induced stresses and deformations that change with the change in temperature (Timoshenko, 1925;Aleck, 1949;Pan und Pao, 1990;Kuo, 1990;Suhir, 1991;2000b;Lau, 1993).…”