B31.1 (1967) - CAESAR II - Help

CAESAR II Users Guide

Language
English
Product
CAESAR II
Search by Category
Help
CAESAR II Version
12

Calculate full-sized intersections for both the header and the branch using B31.1 (1967)

B31.1 (1967) uses ii = io for full-sized intersections for both the header and the branch, and for reduced intersections uses ii = 0.75io + 0.25 for both the header and the branch.

Calculate pressure stiffening using B31.1 (1967)

Pressure stiffening is not defined by default in this code. You can include pressure stiffening on bends in the analysis by including the Use Pressure Stiffening option in the setup file.

Flanged end modifications using B31.1 (1967)

Modifications resulting from flanged ends are permitted in the code providing the bend is not a widely spaced miter.

B31.1 (1967) girth butt welds default value

The default SIF value for a girth butt weld is 1.0. This is also Markl’s original basis for SIFs.

Calculate socket welds using B31.1 (1967)

B31.1 (1967) makes no distinction between socket welds with undercut and socket welds without undercut. Codes that do differentiate use 1.3 for socket welds with no undercut, and 2.1 for all others. Unless you are specifying a fillet weld leg length, use a default SIF value of 1.3.

Calculate the B31.1 (1967) allowable stress limits

Use the equations below to calculate the stress allowables.

Expansion Allowable = f [ (1.25/Eff)(Sc+Sh) - Sl ]

Sustained Allowable = Sh/Eff

Occasional Allowable = Sh/Eff * Occ

Where:

f = Cyclic Reduction Factor

Eff = Longitudinal Weld Joint Efficiency

Sc = Cold Allowable Stress

Sh = Hot Allowable Stress

Sl = Sustained Stress

Occ = Occasional Load Factor (Default is 1.15)