Fatigue Analysis

Long term Damage Prevention

CANEIL personnel have successfully completed a wide range of Fatigue Analysis projects. Protection against failure from cyclic loading, or Fatigue Analysis, is essential when a pressure vessel operates in cyclic service. Utilizing SOLIDWORKS Premium software, CANEIL conducts thorough studies, applying relevant loading conditions to analyze vessel components for potential fatigue, ensuring the structural integrity and reliability of the equipment over time.

General Steps we Follow

Gather all necessary information, including but not limited to:

Perform Fatigue Screening using ASME Sec VIII Div.2 Part 5.

If the fatigue screening criterion indicates that a full fatigue analysis is required, a detailed model of the vessel is created. Following this, a Finite Element Analysis (FEA) is conducted to evaluate the stress levels at critical locations of the vessel. This in-depth analysis helps identify potential areas of concern and ensures that the vessel can safely withstand cyclic loading throughout its operational life.

The stress is linearized at areas of interest. These linearized stress values are then gathered in accordance with ASME Section VIII, Division 2, Part 5. The fatigue analysis criteria are evaluated based on these values to determine if the vessel components are safe for continued operation, ensuring that they meet the required standards for structural integrity and performance.

The following is a summary of just a few of the projects our team has undertaken:

Case Study 1: Butane Treater

A 4 ft diameter Butane Treater in sweet service was operating in cyclic service. Due to the nature of the service it was determined that a fatigue assessment using the criteria from ASME Sec VIII Div.2 part 5.5 was required. A loading history for the treater was established from operating history to determine if a full fatigue analysis was required. The butane treater was modelled in SOLIDWORKS and a simulation was run to determine the stress concentrations in areas of concern for the vessel. The following analyses were conducted and corresponding criteria were checked as part of the Fatigue Assessment:

Loading history which includes all cyclic operating loads was determined using the Rainflow Counting Method from Annex 5-B.4 of ASME Sec VIII Div.2 and Section 5.4.4 from ASTM E1049.
Fatigue analysis screening using Method A from Section 5.5.2.3 of ASME Sec VIII Div.2.
Protection against failure due to cyclic loading was verified by checking the accumulated fatigue damage in the model against the criterion from ASME Sec. VIII Div. 2 Part 5.5.4.2.

Case Study 2: Mol Sieve Tower

A 3 ft diameter Mol Sieve in sweet service was operating in cyclic service. Due to the nature of the service it was determined that a fatigue assessment using the criteria from ASME Sec VIII Div.2 part 5.5 was required. A loading history for the treater was established from operating sequence data, as no historical cyclic operating load data was available, to determine if a full fatigue analysis was required. The mol sieve was modelled in SOLIDWORKS and simulations were completed to determine the stress concentrations in areas of concern for the vessel. The following analyses were conducted and corresponding criteria were checked as part of the Fatigue Assessment:

Fatigue analysis screening using Method A from Section 5.5.2.3 of ASME Sec VIII Div.2.
Protection against failure due to cyclic loading was verified by checking the accumulated fatigue damage in the model against the criterion from ASME Sec. VIII Div. 2 Part 5.5.4.2.

Case Study 3: Condensate Storage Bullet

A 12 ft diameter condensate storage bullet was operating in cyclic service. Due to the nature of the service it was determined that a fatigue assessment using the criteria from ASME Sec VIII Div.2 part 5.5 was required. A loading history for the treater was established from operating history to determine if a full fatigue analysis was required. The number of operating cycles over the operating life of the vessel was determined to be less than the fatigue screen criteria in Table 5.9 of ASME Sec VIII Div. 2 part 5, and therefore a full fatigue analysis was not carried out. The following analyses were conducted and corresponding criteria were checked as part of the fatigue screening assessment:

Fatigue analysis screening using Method A from Section 5.5.2.3 of ASME Sec VIII Div.2.