Relationships between the Pressure Distribution of the Bolt Head Bearing Surface and of the Joint Interface

Abstract

In this paper, the relationships are considered theoretically between the pressure distribution of he bolt head bearing surface and of the joint nterface. And the desired pressure distribution of the bolt head bearing surface from the view point of the interface pressure distribution and the new half angle of the pressure cone to estimate more accurately the effective area of the connecting force are considered. The following results are found. (1) The interface pressure distribution is improved by expanding or moving the pressure distribution f the bolt head bearing surface to the outsideof the bolt head. (2) The pressure distribution of the bearing surface is affected scarcely by the plate thickness. (3) The effective area of the connecting force D_p can be expressed uniformly as the following equation by introducing the new half angle of the pressure cone θ<SUBeq</SUB whose cardinal point is the equivalent pressure effective diameter of the bearing surface d_eq. D_p=d_eq+2T tan θ_eq. (4) d_eq is influenced by the bolt head size, the undercutting diameter of the bearing surface and the material combination of the joint elements. (5) θ<SUBeq</SUB depends upon only the ratio of the plate to the base in Young's modulus.