Stress in V-section band clamps

Abstract

This paper presents an analysis of the stresses in V-section band clamps by examining the correlation between experimental work and theoretical models. Theoretical models incorporating traditional beam-bending theories and allowing for friction were developed to calculate the stress distribution and displacements within the clamps. The theoretical models demonstrated that the normal manufacturing tolerances associated with this type of component, combined with the uncontrolled operating parameters, will produce a wide variation in working stresses.These theoretical models were validated using strain and displacement measurements from a test with a V-section band clamp positioned around rigid anges. The experimental results all fell within the range of stresses predicted by the theoretical models. The paper provides a knowledge base for the rational design of V-section band clamps.

Predicting plastic deformation and work hardening during V-band formation

“…In the latter work the author presented a theoretical model able to predict the stresses and forces generated as the clamp is tightened around a pair of flanges. This was validated by Shoghi et al (2004) using experimental data and Shoghi et al (2003) using finite element analysis. The finite element work was developed further by Shoghi et al (2006) to account for friction in the axial direction when tightening the T-bolt nut and applying an axial load.…”

“…Young's Modulus of 227 GPa, Poisson's Ratio of 0.29, yield stress of 648 MPa and an ultimate tensile strength of 857 MPa, taken from Shoghi et al (2004). For the FE-Analysis the material was defined to be elastic-plastic with linear hardening, as also used in the study of Kiuchi (1973) and with a von-Mises yield function as mentioned in Dixit and Dixit (2008).…”

Contact Pressure Distribution in Joints Formed by V-Band Clamps

“…In the applications being studied here, the flange has a much more substantial geometry than the band and was therefore treated as a rigid body. This approximation was also made in [5] when developing a theoretical model for flat and V-section band clamps. The use of an analytical rigid body that did not require meshing reduced computing time, and the complexity of the contact analysis, enabling it to converge faster.…”

“…Incorporated into this equation was the coefficient of friction μ acting between the contacting surfaces with the effects of friction being accounted for in both the circumferential and transverse directions. However, a previously presented version of this equation [5] neglected the transverse friction effect. To allow the circumferential and transverse effects to be investigated separately, the equation from [7] was modified to separate the transverse coefficient of friction, μ T , and circumferential coefficient of friction, μ c :…”

“…In [5,6] models were developed to study stresses in these clamps during assembly and working conditions. The results from this work suggests a variation in working stresses due to uncontrolled operating parameters and manufacturing tolerances associated with this type of band.…”