A model for simulating the compression stiffness degradation in circular elastomeric bearings due to fatigue

Open Access
Author:
Deng, Pu
Graduate Program:
Civil Engineering
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
May 13, 2013
Committee Members:
  • Gordon Patrick Warn, Thesis Advisor
  • Maria Lopez De Murphy, Thesis Advisor
  • Charles E Bakis, Thesis Advisor
Keywords:
  • elastomeric bearing
  • fatigue
  • compression stiffness
  • simulation
Abstract:
Elastomeric bearings are widely used in bridge and building construction but sustain fatigue damage when subjected to repeated cycles of loading. Previous experimental research demonstrated that significant stiffness degradation can occur in these bearings as a result of fatigue. However, experimental data is quite limited due to the time and cost associated with fatigue testing elastomeric bearings. Due to the limited experimental data, the influence of a number of bearing design parameters, such as geometry, material, and loading on the fatigue behavior are not well understood. As such, it would be of great benefit to have analytical models that are capable of simulating the fatigue behavior so that a broader understanding of how the various design parameters influences the fatigue behavior. In this study, an analytical model was developed using an analytical framework to simulate compression stiffness degradation due to cycles of compressive loading in axially loaded solid circular multi-layer laminated rubber bearings. The model is used to perform a parametric study to identify the influence that maximum load and shape factor have on the stiffness degradation and fatigue life of the bearing. A global variance based sensitivity analysis is performed using the analytical model to identify the relative importance of a number of model factors, e.g. stress range, shape factor, material properties, to which fatigue life and stiffness degradation are most sensitive.