Steven Altstadt

Associate Principal


Steven Altstadt’s primary interest is in strength and behavior of metals with a specialization in fatigue and fracture. He has conducted a wide variety of analyses using finite element analysis, classical methods, industry design codes, and recommended practices. Dr. Altstadt’s past work has included extreme event strength assessments, extreme event strain-based assessments, defect acceptance criteria, fatigue life predictions, and experimental testing, and field monitoring programs. He has conducted large-scale test programs for welded and bolted connections in structural components and pressurized components. Dr. Altstadt has experience with using API 579, BS 7910, ABAQUS finite element software, special purpose fracture mechanics software programs, classical methods, and design documents (e.g., API, ASME, AISC, AASHTO, AWWA, BS, DNV) to calculate defect acceptance criteria, material requirements, remaining fatigue lives, strength, and ductility.

Dr. Altstadt’s graduate work focused on the fracture of TMCP and traditional low-alloy steel-plate structures. He has been using ABAQUS since 2002. He has been involved in large-scale testing since 2000, and has published papers in various engineering journals and conference proceedings.


Engineering Criticality Assessment - Alternative Weld Defect Acceptance Criteria by Engineering Critical Assessment

  • Past project experience includes subsea pipelines, onshore pipelines, jumpers, risers, downhole tubulars, hulls, fixed offshore structures, pressure vessels, piping, tanks, mooring equipment, and chain
  • Failure Assessment Diagram and nonlinear finite element based methods
  • Experience spans conventional stress-based assessments through strain based assessments
  • Corrosion-fatigue and aggressive environments


Component and Performance Evaluation Testing

  • High-cycle and low-cyclic fatigue of various welded joints
  • Strength testing of welded and mechanically fastened joints
  • Burst testing of pressurized components
  • Strain-based pipe testing
  • Full-scale testing of stiffened panels, truss structures, and beams
  • Rotating machinery


Finite Element Analysis

  • Elastic analysis for design code-based fatigue and strength requirements.
  • Nonlinear fracture mechanics and material failure
  • Elastic-plastic and large deformation analysis for various extreme events.
  • Concrete structures
  • Polymer structures


Fitness for Service

  • Assessments of in-service degradation of metal components due to cracking, corrosion wall loss, extreme events, and third-party impact
  • Work done with clients to assess risks and develop risk based inspection programs
  • Planning and execution of field monitoring programs


Peer Review

  • Client’s technical representative for independent assessment of contractor’s design analyses and ECA-based defect acceptance criteria
  • Client’s representative for independent review of third-party fitness for service assessments
  • Client’s representative for evaluating new products and technologies
  • Litigation expert witness


Repair and Rehabilitation

  • Sleeves and clamps for pipelines and various pressurized equipment
  • Bolted and weld connections for onshore and offshore structures
Professional Affiliations

American Society of Civil Engineers
American Society of Mechanical Engineers
API/ASME Fitness-For-Service Committee 
ASTM International - Committee E08 Voting Member, Committee F16 Voting Member


Professional Engineer in FL, IA, ID, IL, IN, KS, KY, MD, ME, MI, MN, MO, MT, NC, ND, NE, NJ, NV, NY, OH, SC, SD, TX, VA, WI, and WV


University of Minnesota
Bachelor of Science, Civil Engineering, 2002
Master of Science, Civil Engineering, 2004

Purdue University
Doctor of Philosophy, Civil Engineering, 2008