Caleb Roepke
Caleb T. Roepke, Ph.D., P.E., CWI
Managing Engineer
Materials & Corrosion Engineering
Phoenix

Dr. Roepke general areas of expertise include welding engineering, metallurgy, failure analysis, non-destructive evaluation, fatigue and fracture, and corrosion. He specializes in assessment of welded structures and components, welding process development and optimization, and welding metallurgy across a wide range of materials and processes. He has experience in a variety of industries including oil & gas, shipbuilding, construction, and consumer electronics. Dr. Roepke has a particular interest in helping non-specialists understand and find solutions to complex metallurgical and welding challenges.

Prior to joining Exponent, Dr. Roepke was Fabrication Group Lead and a Senior Materials Engineer for ExxonMobil working on large scale upstream project development. Dr. Roepke assisted multiple engineering, construction, and manufacturing companies often onsite in a variety of locations around the world to find solutions to urgent welding and metallurgical problems. Dr. Roepke gained extensive experience helping internal project teams and external contractors by conducting root cause analysis, optimizing welding processes, developing non-destructive evaluation techniques, conducting corrosion studies, leading failure investigations, qualifying materials and welding processes, participating in fit-for-purpose evaluations, and overseeing fabrication.

Dr. Roepke’s academic work at the Colorado School of Mines investigated various phenomena in hybrid laser arc welding on steel and aluminum. Specifically, the effect of laser beams of various power levels incident on an arc welding pool were studied, demonstrating that high power laser beams resulted in high welding speeds and penetrations, whereas lower laser powers increased the stability of the welding arc. Dr. Roepke used high speed video to visualize the welding plasma, weld pool surface, and metal transfer; analyzed the arc welding electrical signals; and performed metallurgical examinations to examine the weld macrostructure and microstructure. Dr. Roepke taught welding and metallurgy in the classroom and the laboratory (and is still quite adept under a welding hood).

CREDENTIALS & PROFESSIONAL HONORS

  • Ph.D., Metallurgical and Materials Engineering, Colorado School of Mines, 2010
  • B.S., Engineering, LeTourneau University, 2005

LICENSES & CERTIFICATIONS

Licensed Metallurgical Engineer, California, #1996

Certified Welding Inspector (CWI), American Welding Society, #16082841

Publications

Nissley N, Noecker R, Anderson T, Roepke C, Hukle M, Gallagher M. Dissimilar metal welding of nitronic 50HS and 25%Cr super duplex stainless steel. 33rd International Conference on Ocean, Offshore and Arctic Engineering, OMAE2014-24706, 2014.

Roepke C, et al. Process monitoring and macrostructure examination of low laser power hybrid gas metal arc welding on A36 steel. 63rd International Institute of Welding Annual Assembly and International Conference, IIW Doc. IV-1030-10, 2010.

Roepke C, et al. Low power laser hybrid gas metal arc welding on A36 steel. MS&T 2010; 4:2775–2786.

Roepke C, Liu S, Kelly S, Martukanitz R. Hybrid laser arc welding process evaluation on DH36 and EH36 Steel. Welding Journal 2010; 89(7):140S–149S.

Roepke C, Liu S. Hybrid laser arc welding of HY-80 steel. Welding Journal 2009; 88(8):159S–167S.

Presentations

Roepke C. Hybrid laser arc welding of DH-36 and EH-36 steel: Characterization of the macrostructure, microstructure, and welding parameters. Presentation at the AWS Conference, 2008.

Roepke C. Characterization of the macrostructure and microstructure in hybrid laser arc welding of HY-80 steel. Presentation at the WS Conference, 2007.

Prior Experience

Fabrication Group Lead and Senior Materials Engineer, ExxonMobil, 2010–2016

Graduate Student Instructor, Colorado School of Mines, 2005–2010

Welding Research Assistant, Los Alamos National Laboratory, Summer 2004

Welding Engineering Intern, Newport News Shipbuilding, Summer 2003 & 2002

Professional Affiliations

ASM International

American Welding Society – AWS

NACE International

CREDENTIALS & PROFESSIONAL HONORS

  • Ph.D., Metallurgical and Materials Engineering, Colorado School of Mines, 2010
  • B.S., Engineering, LeTourneau University, 2005

LICENSES & CERTIFICATIONS

Licensed Metallurgical Engineer, California, #1996

Certified Welding Inspector (CWI), American Welding Society, #16082841