Expansion Joint Deformation

This table displays linear and rotational expansion joint deformation as projections on coordinate axes. Linear deformation is mutual pipe end displacement, while rotational deformation is mutual rotation of pipe ends. Deformation sign depends on the direction of local axes of elements adjoining the expansion joint.

For universal expansion joints the relative displacements of flexible joint (deformations) are checked using the following summary equation:

If allowable torsion rotation available, then 4th member is added to the equation above

For axial expansion joint the summary calculated as equivalent axial deformation x divided by allowable axial deformation xa:

Lb – Corrugated length of bellows

Lu – Distance between outermost ends of convolutions

Dm – Mean diameter of bellows convolutions

For single use compensators, deformation values for the welding moment are displayed (at welding temperature input in Project Settings).

Table view and contents depend on two properties, which must be input:

Property	Description
Operating Mode	Choose operation mode for which the results will be displayed Maximum - the maximum value will be displayed in every cell from all operation modes Here you can see analysis results from each of additional force-based loading, seismic, wind, and ice loading
Design state selection	For every operating mode software calculates several submodes (piping states) Maximum value (abs.) - maximum deformation values (for the absolute value) are displayed for each axis in all states (Operation state, Cold state, Test state, After welding single use compensators) Operating mode with pressure Operating mode with no pressure Cold mode After welding single use compensators After testing For more information, see force and effect combination.
Occasional Loads	Maximim + Seismic. Seismic load cases are considered Maximum and minimum + Seismic
Axis	Linear and rotational expansion joint deformation is displayed as projections on coordinate axes: Local Axis (Design/Allowable) (Xm, Ym, Zm) - in local expansion joint coordinate system with calculation of design axial, shear, angular bending and angular torsion deformation. The values are compared to allowable ones Global Axis (X, Y, Z) - Δ_X, Δ_Y, Δ_Z, φ_X, φ_Y, φ_Z (fig. 1.a) Local Axis (Xm, Ym, Zm) - in local element coordinate system Δ_Xm, Δ_Ym, Δ_Zm, φ_Xm, φ_Ym, φ_Zm (fig. 1.b) Fig. 1. Expansion joint deformation in global (general) and local coordinate systems

Notes

Note	Description
Expansion joint skew exceeds allowed	Expansion joint skew conditions not met . More...
Deformation exceeds axial expansion	Condition not met. Actual equivalent axial deformation exceeds allowable axial expansion Δ_k. Piping model or expansion joint properties must be changed. More...
Deformation exceeds rotational expansion	Actual rotational deformation exceeds allowable rotational expansion. Piping model or expansion joint properties must be changed.
Deformation exceeds lateral expansion	Actual lateral deformation exceeds allowable lateral expansion. Piping model or expansion joint properties must be changed.

Menu Access

After analysis: Output > Expansion Joint Deformations