The straight and curved parts of the BM3 model are meshed with pipe (PIPE289) and elbow (ELBOW290) elements, respectively:

Figure 12.2: BM3 Model Meshed with PIPE289 and ELBOW290 Elements

The default settings for the PIPE289 and ELBOW290 elements apply.

To more accurately capture the curvature of a bend, it is divided into four parts, and each part is meshed with ELBOW290.

The section properties (SECTYPE and SECDATA) of the pipe and elbow elements are defined via the following input:

SECTYPE,SECID1,PIPE,ctube     ! "SECID1" is a user-specified name
SECDATA,3.5,0.216             ! Outside diameter and wall thickness 

SECTYPE,SECID2,PIPE,ctube     ! "SECID2" is a user-specified name
SECDATA,4.5,0.2370            ! Outside diameter and wall thickness

SECTYPE,SECID3,PIPE,ctube     ! "SECID3" is a user-specified name 
SECDATA,8.625,0.322           ! Outside diameter and wall thickness

Each elastic support of the piping system is modeled as a spring element (COMBIN14):

Figure 12.3: Elastic Supports Meshed with COMBIN14 Elements

One-dimensional longitudinal and torsional springs are defined via element key options (KEYOPT(2) = 1 through 6).