Effect of Space Angle of Constriction Resistance and Contact Resistance for the Case of Line Contact

It can generally be considered that an actual contact makes an angle with the extension of the contact surface, because the tip of a contact element is convex in shape (macroscopically) and has surface roughness (microscopically). There are, however, few studies that have taken into account the effect of this angle on the constriction resistance or the contact resistance. A line contact is taken as an example, and the effect of space angle is analyzed theoretically by solving Laplace´s equation subject to boundary conditions determined by a modeled morphology of the contact. The analysis leads to modified formulas for the constriction resistance and the contact resistance, which show that the effect can not always be neglected.