Equivalent Stiffness Evaluations of Clamped Plates in Bolted Joints under Loading

概要

論文の詳細を見る
The equivalent stiffness of clamped plates should be prescribed not only to evaluate the strength of bolted joints but also to evaluate deformation and vibration characteristics of practical structures with many bolted joints. The axial stiffness and bending stiffness of clamped plates were evaluated by using Finite Element (FE) analyses while taking the contact condition on bearing surfaces and between the plates into account. We constructed the FE models for bolted joints tightened with M8, 10, 12 and 16 bolts and plate thicknesses of 3.2, 4.5, 6.0 and 9.0 mm, and the axial and bending compliances were precisely evaluated. These compliances of clamped plates were compared with those from VDI 2230 codes (German Engineering Society), in which the equivalent cylindrical and conical compressive stress fields in the plate had been assumed. The compliances of the clamped plates for the preload states were estimated between the predictions as the cylindrical and the conical fields. Meanwhile, the axial and bending compliances of FE analysis can basically be expressed by the VDI 2230 (2003) with the conical field. However, the VDI 2230 (2003) gives the slightly large axial stiffness, and thus the internal force borne to the bolt is predicted in a little bit dangerous failure. Also, it cannot follow the case of clamped plates with different thickness due to assumption of its model.