Overview
This article explains how stresses and allowable stresses are calculated during rigging analysis in AutoPIPE Vessel, including the methodology for stress evaluation and the determination of maximum allowable compressive stresses according to ASME Section VIII, Division 1.
1. Stress Calculation
AutoPIPE Vessel analyzes bending moments and shear forces using a simply supported beam model.
The evaluation employs a reduction process based on Falk’s transmission matrix method, which simplifies the structural analysis for rigging conditions.
2. Maximum Allowable Compressive Stresses
The maximum allowable compressive stresses are determined as described in the Stress Calculation page under Vessel under Combination Loading – Definitions.
Refer to ASME Section VIII, Division 1, UG-23 for detailed requirements.
3. Calculation Steps for Maximum Allowable Compressive Stresses
According to ASME Section VIII, Division 1, UG-23, follow these steps:
- Calculate Factor A:
Using the selected values of t (thickness) and Ro (outside radius), compute: A=0.125/(Ro/t) - Determine Material Chart Value:
Using the calculated A, enter the applicable material chart in ASME Section II, Part D, Subpart 3 for the material under consideration. - Compute Maximum Allowable Compressive Stress (B):
From the chart, obtain the value of B, which represents the maximum allowable compressive stress for the given conditions.
See Also