Metal and composite components used in structural engineering not only contain geometrical features resulting in stress concentration phenomena, but they are also subjected to in-service multiaxial fatigue loading. To address the problem, structural engineers need reliable methodologies which allow for an adequate margin of safety. The book summarises methods devised by the author to design real components against multiaxial fatigue by taking full advantage not only of nominal but also of local stress-strain quantities. The book begins by reviewing definitions suitable for calculating the stress-strain quantities commonly used to perform fatigue assessment. The Modified Wöhler Curve Method is then explained in detail, by focusing attention on both the high- and the medium-cycle fatigue regime. The existing links between the multiaxial fatigue criterion and physical properties are also discussed. A procedure suitable for employing the method developed by the author to estimate fatigue damage both in notched and in welded components is explained. The Modified Manson-Coffin Curve method is investigated in depth, by reviewing those concepts playing a fundamental role in the so-called strain based approach. Lastly, the problem of performing the fatigue assessment of composite materials is addressed by considering design parameters influencing composite behaviour under complex cyclic loading paths and those criteria suitable for designing real components against multiaxial fatigue. The book also contains two appendices summarising experimental data from the technical literature. These appendices provide a unique and highly valuable resource for engineers. The appendices summarise around 100 values of the material characteristic length L, experimentally determined by testing specimens made of different engineering materials and about 4500 experimental fatigue results generated by testing plain, notched and welded specimens under constant-amplitude proportional and non-proportional multiaxial fatigue loading are listed. Summarises methods devised by the author to design real components against multiaxial fatigue Reviews definitions suitable for calculating the stress-strain quantities commonly used to perform fatigue assessment Includes an in-depth explanation of both the Modified Wöhler Curve and Modified Manson-Coffin Curve Method
|Release Date||: 2018|
|Pages||: 329 pages|
Abstract: Many components in engineering applications are subjected to multiple and uncorrelated loads during service‐life. Thus, multiaxial stress states with rotating principal axis may occur. For this special case of multiaxial and non‐proportional stresses the results of many fatigue assessment methods which are used in the industrial practice are of poor quality. Fatigue lifetimes of shoulder shafts (quenched and tempered steel) are estimated on the basis of the extended short crack model in combination with a multiaxial notch approximation. This approach shows a high accuracy but the precise modelling of non‐proportional hardening effects requires a complex plasticity model. Therefore, a simplified approach for considering non‐proportional hardening is introduced. Thus, the calculation method gets applicable in the engineering practice. Results are compared to well‐established engineering approaches. Furthermore, new component tests on die‐cast housings with two load channels under constant and variable amplitude loading are presented and discussed. The loads are applied in‐phase (proportional) as well as out‐of‐phase, which results in a high non‐proportional stress path at the crack initiation site. The effects of multiaxial and non‐proportional stress states seem to play a minor role in the fatigue assessment of die‐cast housings.
Papers presented at the ASTM Symposium on Multiaxial Fatigue, held in San Diego, November 1991, to communicate the most recent international advances in multiaxial cyclic deformation and fatigue research as well as applications to component analysis and design. The 24 papers are grouped into five ca
This volume contains 18 papers selected from 90 presented at the Fifth International Conference on Biaxial/Multiaxial Fatigue and Fracture held in Cracow, Poland 8-12 September 1997. The papers in this book deal with theoretical, computational and experimental aspects of the multiaxial fatigue and fracture of engineering materials and structures. The papers are divided into the following four categories: 1. Proportional cyclic loading 2. Non-proportional cyclic loading 3. Variable amplitude and random loading 4. Crack growth Most papers in this publication talk about the behaviour of constructional materials and elements of machines under non-proportional loading and under variable amplitude and random loading, which are more realistic load histories met in industrial practice. Variable amplitude loading under cyclic load with basic frequency and random loading under load with a continuous band of frequency is classified here. This book gives a review of the latest world success and directions of investigations on multiaxial fatigue and fracture. More and more often publications are results of the co-operation of researchers from different laboratories and countries. Seven out of eighteen papers included here were worked out by international authors teams. This is a symptom of the times, when science and investigations know no borders.
This volume contains the edited version of lectures and selected research contributions presented at the NATO ADVANCED STUDY INSTITUTE on ADVANCES IN FATIGUE SCIENCE AND TECHNOLOGY. held in Alvor. Portugal, 4th to 15th of April 1988. and organized by CEMUL - Center of Mechanics and Materials of The Technical University of Lisbon. The Institute was attended by 101 participants, including 15 lecturers. from 14 countries. The participants were leading scientists and engineers from universities, research institutions and industry. and also Ph.D~ students. Some participants presented papers during the Institute reporting the state-of-art of their research projects. All the sessions wel'e very active and quite extensive discussions on scientific aspects took place during the Institute. The Advanced Study Institute provided a forum for interaction among eminent scientists and engineers. from different schools of thought and young researchers. The Institute addressed the foundations and current state of the art of essential aspects related to fatigue science and technology, namely: Short Cracks, Metallurgical Aspects, Environmental Fatigue, Threshold Behaviour, Notch Behaviour. Creep and Fatigue Interactions at High Temperature, Multiaxial Fatigue, Low Cycle Fatigue, Methodology of Fatigue Testing, Variable Amplitude Fatigue, Fatigue of Advanced Materials. Elastic-Plastic Fatigue, and several engineering applications such as welded joints, energy systems, offshore structures, automotive industry, machine and engine components. This book is organized in three parts: Part I: Fundamentals of Fatigue Part II: Engineering Applications Part III: Research Contributions The research contributions covered most of the areas referred above.
This volume contains a selection of papers presented at Fatigue Design 95 held in Helsinki, Finland from 5-8 September 1995. The papers have been peer reviewed and present practical aspects for the design of components and structures to avoid fatigue failure. Topics covered include: fatigue design experiences, ground vehicle components, component reliability, multiaxial fatigue, notch analysis, service loading, welded structures, probabilistics aspects in fatigue, fatigue design optimization.
The European Structural Integrity Society (ESIS) Technical Commitee on Fatigue of Engineering Materials and Structures (TC3) decided to compile a Special Technical Publication (ESIS STP) based on the 115 papers presented at the 6th International Conference on Biaxial/Multiaxial Fatigue and Fracture. The 25 papers included in the STP have been extended and revised by the authors. The conference was held in Lisbon, Portugal, on 25-28 June 2001, and was chaired by Manual De Freitas, Instituto Superior Tecnico, Lisbon. The meeting, organised by the Instituto Superior Tecnico and sponsored by the Portuguese Minesterio da Cienca e da Tecnologia and by the European Structural Integrity Society, was attended by 151 delegates from 20 countries. The papers in the present book deal with the theoretical, numerical and experimental aspects of the Multiaxial fatigue and fracture of engineering materials and structures. They are divided in to the following six sections; Multiaxial Fatigue of Welded Structures; High cycle Multiaxial fatigue; Non proportional and Variable-Amplitude loading; Defects, Notches, Crack Growth; Low Cycle Multiaxial Fatigue; Applications and Testing Methods. As is well-known, most engineering components and structures in the mechanical, aerospace, power generation, and other industries are subjected to multiaxial loading during their service life. One of the most difficult tasks in design against fatigue and fracture is to translate the information gathered from uniaxial fatigue and fracture tests on engineering materials into applications involving complex states of cyclic stress-strain conditions. This book is the result of co-operation between many researchers from different laboratories, universities and industries in a number of countries.
Contains papers from a May 1999 symposium, describing state-of-the-art multiaxial testing techniques and analytical methods for characterizing fatigue and deformation behaviors of engineering materials. Papers are classified into sections on multiaxial strength of materials, multiaxial deformation,
|Author||: Jie Fang|
|Publisher||: Herbert Utz Verlag|
|Release Date||: 2015-07-23|
|ISBN 10||: 3831644845|
|Pages||: 152 pages|
The present work aims at engineers and scientists in the field of computational mechanics of materials. The objective of this work is to develop a suitable constitutive law and apply it to study effects of cyclic loading and geometry on the fatigue assessment. Firstly, a systematical investigation on the mechanic behaviors of an austenitic stainless steel is carried out. Different multiaxial fatigue life prediction models are studied to assess fatigue damage. The Karim-Ohno kinematic hardening model is extended to incorporate more complex mechanical behaviors. The proposed constitutive model is implemented into FEM code ABAQUS. Finally a computational fatigue analysis methodology is proposed for performing life prediction of notched components based on elastic-plastic computation.
|Author||: Magd Abdel Wahab|
|Publisher||: Springer Nature|
|Release Date||: 2021-01-13|
|ISBN 10||: 9811591210|
|Pages||: 503 pages|
This book comprises the select proceedings of Structural Damage Modelling and Assessment (SDMA 2020) presented online on 4–5 August 2020. It discusses the recent advances in fields related to damage modelling, damage detection and assessment, non-destructive testing and evaluation, structure integrity and structural health monitoring. The conference covers all research topics and applications relevant to structural damage modelling and assessment using theoretical, numerical and experimental techniques. This book is useful to scientists and engineers in academia and industry who are interested in the field of structural damage and integrity.