Engineering Articles

Engineering

• Introduction to Fatigue Analysis – Explains how cyclic loading causes crack initiation and propagation in mechanical components, covering low-cycle vs. high-cycle fatigue, S-N curves, and the three main design approaches for preventing fatigue failure.
• History of Fatigue Analysis – Traces the development of fatigue science from Wöhler’s 19th-century rail axle tests through the fracture mechanics advances of Paris, Coffin, and Manson, including O’Donnell’s direct role in shaping the ASME fatigue code.
• Introduction to Failure Analysis – Describes the systematic, interdisciplinary process used to determine the root cause of component failures, from corrosion and material defects to design flaws and operational error
• Introduction to Fracture Mechanics – Covers the theoretical and practical framework for predicting crack growth in structural materials, including stress intensity factors, fracture toughness, and the Paris Law for fatigue crack propagation
• Introduction to Metallurgy – Provides a foundational overview of how metal composition, microstructure, and processing affect mechanical properties, with practical coverage of hardness, tensile, and fatigue testing used in engineering investigations.
• When to Call a Metallurgist – When components made of metal fail, this is typically the first reaction. It’s a fact of life – things break. Learn more about when to call a metallurgist and what’s involved
• Introduction to Nondestructive Testing – Surveys the principal NDT methods — including ultrasonic, radiographic, magnetic particle, and dye penetrant techniques — used to detect flaws in pressure vessels and structural components without causing damage
• Background to ASME B31 Code – Explains the origins and structure of the ASME B31 pressure piping code, covering its sections, design philosophy, and the requirements engineers must meet for compliant piping system design.
• Background to API 579 / ASME 579 Code – Introduces the fitness-for-service standard used to assess whether aging or damaged pressure equipment can continue safe operation, including the tiered assessment methodology at the heart of API 579/ASME FFS-1

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Pressure Vessel Design & Analysis

• Stress Analysis of Thin Walled Pressure Vessels – Derives the fundamental hoop and longitudinal stress equations for cylindrical pressure vessels, providing the analytical basis for understanding wall thickness requirements and design margins.
• Basics of Pressure Vessel Design & Analysis – Introduces the core concepts of pressure vessel engineering, including design loads, code requirements, material selection, and the distinction between primary and secondary stresses.
• Design by Analysis vs. Design by Rule – Compares the two ASME design philosophies — prescriptive rule-based methods and the more rigorous stress analysis approach — explaining when each is appropriate and what analytical depth DBA requires.
• What is a Primary Stress – Clarifies the often-misunderstood distinction between primary and secondary stresses in pressure vessel design, and why the classification directly determines the applicable ASME code limits and analysis methods.
• Overview of ASME Design by Analysis – Provides a structured overview of the ASME B&PV Code Design by Analysis methodology, including stress linearization, stress categories, and the evaluation criteria used in Section VIII, Division 2 analysis.
• Understanding ASME Code Requirements – Guides engineers through the organization of the ASME Boiler and Pressure Vessel Code, explaining the purpose of each major section and how the requirements interact across design, fabrication, and inspection.
• Performing Fatigue Analysis on Pressure Vessels – Walks through the practical application of ASME fatigue evaluation procedures for cyclic pressure vessels, including fatigue curve usage, cycle counting, and cumulative damage assessment.
• Common Mistakes in Pressure Vessel Analysis – Identifies the most frequent errors engineers make in pressure vessel stress analysis — misclassifying stresses, misapplying code equations, and overlooking local discontinuities — and how to avoid them.
• Introduction to ASME Code Design Approval – Explains the ASME design approval process for pressure vessels, covering the roles of the Authorized Inspector, the Manufacturer’s Design Report, and the documentation required for code stamp certification.