Tetra Engineering
"Data to Decisions"

Copyright © Tetra Engineering Inc.
All rights reserved.
Last Updated:
19-jan-06 17:25 CET

Click here if you want to download a failure analysis request form.

Root cause failure analysis is often analogous to solving a complex puzzle. It requires the integration of wide range of engineering skills, knowledge, and experience. The function of the component must be understood along with the materials of construction, service history, environmental factors, and failure mechanisms. Tetra Engineering uses an interdisciplinary team approach to solve these complex problems.

We have experts in:

All of our senior personnel have greater than twenty years experience in their respective discipline.

A typical root cause analysis begins with a site visit to observe, photograph, and document the failure, collect samples and other evidence, interview personnel, and obtain historical information. This is usually followed by a metallurgical evaluation to establish failure mechanisms such as tensile overload, fatigue, stress corrosion etc.

Our lead analyst reviews the system operation, historical records, environment and other relevant information to fully establish the root cause of the failure, drawing expertise from other disciplines as required. Often finite element models of the component or system will be constructed to fully quantify stresses, fluid velocities, temperatures, or other pertinent parameters.

Material Testing Services
Our failure analyses often include metallurgical examinations and materials tests. These may include:

Finite Element Analysis
Finite element analysis (FEA) is a numerical technique used to solve mathematical computer models of real world components and materials. Applications that can be modeled include complex structural components with heat transfer and fluid flow. FEA can be used to determine:

The power of the finite element analysis method lies in its versatility, its applications are virtually unlimited. However, to define a good FEA model and generate useful results, experience, good engineering judgment, and understanding of FEA computer software capabilities are vital. Commercial software packages and the required hardware are available but an inexperienced user can easily produce incorrect results upon which expensive decisions will be based. The analyst must be able to tell whether the computed results are accurate and consistent with physical reality. This is where Tetra Engineering’s engineers experience contributes greatly to the value of the analysis to the client.

Finite element analysis can be used to support root cause failure analysis or to confirm / enhance initial designs prior to being placed in service. Any flaws in an initial design or in-service component can be quickly identified. Thus, new components can be reliably placed in service or failed components redesigned to prevent reoccurrence of failures. Alternate scenarios of component design and operation can be easily explored to optimize design integrity and to keep costs low.

Fitness for Service
It is not necessary to wait for components to fail. Tetra Engineering can perform fitness for service evaluations of tanks, vessels, structures, rotating equipment and other industrial components. We employ applicable codes such as ASME Boiler and Pressure Vessel Code, European PED and American Petroleum Institute API 579 Fitness for Service guidelines. Our engineers can provide complete fitness for service, mechanical and pressure boundary integrity, corrosion assessments, and remaining life analyses.

Expert Witness Services
Tetra Engineering provides root cause failure analysis and engineering expert witness services to legal, insurance, and industrial firms to determine the cause of equipment failures. Our extensive experience gives us credibility in expert witness testimony involving equipment defect/ warrantee issues, structural failures, and corrosion failures. Our opinions are based on detailed quantitative engineering calculations and analysis backed by technical literature reviews and experience as practicing engineers.

Our expert reports are thorough, comprehensive, and written in a manner that can be easily understood by lay people, they incorporate professional exhibits and graphics that effectively demonstrate and communicate fundamental principles and the results of our analysis.