model elastomeric bearing in midas civil

The bi-linear model was provided by many design software, and convenient for the numerical calculation (MIDAS Soft 2019 Computers and Structures 2018).

In the bi-linear mechanical model, yielding force was assumed to be the product of its gravity load and the frictional coefficient at the contact interface. The classical bi-linear model was one of the most commonly used models in bridge engineering owing to its simplicity and efficiency (Wei et al. equivalent linear model, bi-linear model, modificatory bi-linear model and Bouc-Wen model et al. In horizontal direction, many mechanical models were developed to simulate the friction restoring force of rubber bearings, i.e. In practical design, the rubber bearing was simplified as a linear spring both in vertical compression and tension. In general, the rubber bearing has very large compressive stiffness and load-carrying capacity in vertical direction, and provides frictional restoring force in horizontal directions (Yang et al. basin-type rubber bearing and panel-type rubber bearing. Rubber bearings were widely used in bridge engineering owing to its economy, durability and easy construction, i.e. The bi-linear bearing model would underestimate the seismic demand of the bearing and piers. The analysis results indicated that the different bearing model led to the significant different seismic response for the bearings and piers, even the vertical component was small. The intensity measure was selected as the ratio of the peak ground acceleration (PGA) in the vertical direction to the PGA in the horizontal direction. A typical continuous beam bridge was modeled in ABAQUS, and incremental dynamic analysis was conducted for the quantitative comparison of the seismic responses using different bearing models. This paper developed a nonlinear frictional bearing model, which can consider the variation of the frictional restoring force in the bearings, even the separation with the beam in vertical directions. Employing the bi-linear model for the bearing may incorrectly estimate the seismic response of the bearings, as well as the whole bridge. However, in actual earthquake, the rubber bearing suffered fluctuating axial pressure in earthquake, even separated from the beam when vertical component of the earthquake was too strong. In the seismic design of long-span bridges, the classic bi-linear model was used to simulate the frictional restoring force of the rubber bearings.

Model elastomeric bearing in midas civil