Session: FSI-02-09 FSI Applications III

Paper Number: 152227

152227 - Wind-Induced Vibration of Tall, Slender Process Columns 

Abstract: 

Over the years, vertical pressure vessels have trended towards taller, more slender designs as owner-users seek to optimize equipment footprint while maximizing production output. However, with these benefits comes an increased risk of certain failure modes that may not have been as prominent in older designs. One such risk is transverse wind-induced vibration (WIV), a phenomenon that affects tall, slender structures subjected to wind loads.

As more in-service equipment adopt these designs, a greater proportion of vertical vessels are becoming susceptible to WIV, which can pose significant threats if not properly accounted for during design, erection, and operation. Unmitigated WIV can lead to mechanical overstress or fatigue failure, both of which carry severe consequences. Failures resulting from such vibration not only compromise the integrity of the equipment but also present serious risks in terms of personnel safety, environmental damage if failure occurs during operation, and financial losses. Repair or replacement of damaged equipment can result in substantial costs, and downtime in operations can lead to further economic repercussions.

While WIV of tall, slender, cylindrical structures has been studied extensively over the years, there is a lack of consensus amongst various international codes and standards (or, in some cases, complete omission of any consideration for WIV as is the case in ASME and ASCE codes) regarding how best to assess and mitigate this issue. The published research on this topic, though extensive, does not present a unified analysis approach for the wide variety of equipment seen in service today. 

This study utilizes literature review, analytical methods, and real-world case studies to provide insight into the current state of practice regarding process column WIV.  A review of relevant principles of aerodynamics and structural dynamics, various methods for assessing susceptibility to WIV, methods for predicting peak response and number of cycles for fatigue evaluation, and appropriate values for the critical structural damping parameter are presented.  Methods available in published codes and standards are discussed, and the limits and gaps associated with various WIV assessment techniques are identified.  Mitigation techniques for WIV are also discussed.  Case studies are presented to demonstrate how severe WIV response has been overlooked in design leading to premature structural failures.  Best practices for assessing WIV are suggested along with recommendations for future implementation in relevant industry codes & standards.

The goal of this study is to improve the state of practice related to process column WIV, reduce the overall risk for in-service equipment, and suggest a path forward for industry to address this issue which is likely to become increasingly prevalent over time given trends in the process equipment design.  This information is relevant to engineers and stakeholders with interest in a variety of tall, slender structures not limited to process columns, including steel stacks, wind turbine masts, etc.   

Presenting Author: Derek Slovenec The Equity Engineering Group, Inc.

Presenting Author Biography: Dr. Slovenec is a Senior Engineer and Group Head at E2G. He serves as the company's technical authority on civil/structural engineering. He also regularly performs fitness for service assessments of pressure vessels and aboveground storage tanks. Dr. Slovenec serves on the wind, seismic, and general requirements subcommittees for ASCE 7-28.

Authors:

Derek Slovenec The Equity Engineering Group, Inc.
Gaurav Mittal The Equity Engineering Group, Inc.