Session: SE-03-01 Damping and Vibration Control

Paper Number: 61733

Start Time: Tuesday, July 13, 2021, 05:00 PM

61733 - Effect of Shape Modeling on FEM Analysis Results of Equal Tee Pipe 

Piping systems are widely used in power plants and industrial facilities, and it is very important to ensure the seismic safety of them under excessive seismic events. It is known that the expected failure mode of piping systems under excessive seismic motion would be the fatigue failure at elbows or tees. Although there are a lot of experimental and analytical investigations on the strength and the failure behavior of elbows under seismic loading, there are a few studies on tee pipe joints, particularly in the inelastic range. In addition, the investigations on characteristics of actual tee pipes’ shapes are very few, though it is known that the shape of actual tee pipes has some deviation from the nominal value and it would affect the analytical results.

To understand the feature of the actual tee pipe’s shape and the effect of shape modeling on FEM analysis results, the authors measured the 3-D shape of a 150A equal tee pipe, and conducted inelastic static analysis and modal analysis on a pipe specimen including the equal tee pipe. The tee pipe joints used in this investigation was a “steel butt-welding type” carbon steel tee pipe joint. The material property was modeled by bi-linear kinematic hardening in the inelastic analysis. Two kinds of shape data for FEM analytical models were prepared; one was based on the measured configuration, and the other was based on the nominal dimension. In this paper, the effect of shape modeling on the load-displacement relationship, the strain concentration position, and the modal analysis results are discussed.

Presenting Author: Izumi Nakamura National Research Institute for Earth Science and Disaster Resilience

Authors:

Izumi Nakamura National Research Institute for Earth Science and Disaster Resilience
Tadahiro Shibutani Yokohama National University