Fatigue Life Prediction of Notched Components; Comparison of Method with Existing Fatique Data PDF Download

Author: Toney A. Wilson
Publisher:
ISBN:
Category :
Languages : en
Pages : 35

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Author: Tom Lassen
Publisher: John Wiley & Sons
ISBN: 1118614704
Category : Technology & Engineering
Languages : en
Pages : 442

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Book Description
Avoiding or controlling fatigue damage is a major issue in the design and inspection of welded structures subjected to dynamic loading. Life predictions are usually used for safe life analysis, i.e. for verifying that it is very unlikely that fatigue damage will occur during the target service life of a structure. Damage tolerance analysis is used for predicting the behavior of a fatigue crack and for planning of in-service scheduled inspections. It should be a high probability that any cracks appearing are detected and repaired before they become critical. In both safe life analysis and the damage tolerance analysis there may be large uncertainties involved that have to be treated in a logical and consistent manner by stochastic modeling. This book focuses on fatigue life predictions and damage tolerance analysis of welded joints and is divided into three parts. The first part outlines the common practice used for safe life and damage tolerance analysis with reference to rules and regulations. The second part emphasises stochastic modeling and decision-making under uncertainty, while the final part is devoted to recent advances within fatigue research on welded joints. Industrial examples that are included are mainly dealing with offshore steel structures. Spreadsheets which accompany the book give the reader the possibility for hands-on experience of fatigue life predictions, crack growth analysis and inspection planning. As such, these different areas will be of use to engineers and researchers.

Author: N. Chen
Publisher:
ISBN:
Category : Crack closure
Languages : en
Pages : 16

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A 2-D analytical model which is termed the PICC-RICC model combines the effects of plasticity-induced crack closure (PICC) and roughness-induced crack closure (RICC). The PICC-RICC model handles naturally the gradual transition from RICC to PICC dominated crack growth. In this study, the PICC-RICC model is combined with a crack nucleation model to predict the total fatigue life of a notched component. This modified PICC-RICC model will be used to examine several controversial aspects of an earlier, computationally simpler total-life model known as the IP model.

Author: Michael R. Mitchell
Publisher: ASTM International
ISBN: 0803114230
Category : Fracture mechanics
Languages : en
Pages : 495

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Book Description
Twenty-seven papers from fatigue researchers and practitioners review in detail recent progress in the development of methods to predict fatigue performance of materials and structures and to assess the extent to which these new methods are finding their way into practice. The papers, from the ASTM

Author: Dino Anthony Celli
Publisher:
ISBN:
Category : Additive manufacturing
Languages : en
Pages : 0

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The fatigue life prediction framework developed and described in the proceeding chapters can concurrently approximate both typical stress versus cycle (SN) behavior as well as the inherent variability of fatigue using a limited amount of experimental data. The purpose of such a tool is for the rapid verification and quality assessment of cyclically loaded components with a limited knowledge-base or available fatigue data in the literature. This is motivated by the novelty of additive manufacturing (AM) processes and the necessity of part-specific structural assessment. Interest in AM technology is continually growing in many industries such as aerospace, automotive, or bio-medical but components often result in highly variable fatigue performance. The determination of optimal process parameters for the build process can be an extensive and costly endeavor due to either a limited knowledge-base or proprietary restrictions. Quantifying the significant variability of fatigue performance in AM components is a challenging task as there are many underlying causes including machine-to-machine differences, recycles of powder, and process parameter selection. Therefore, a life prediction method which can rapidly determine the fatigue performance of a material with little or no prior information of the material and a limited number of experimental tests is developed as an aid in AM process parameter optimization and fatigue performance qualification. Predicting fatigue life requires the use of a previously developed and simplistic energy-based method, or Two-Point method, to generate a collection of life predictions. Then the collected life predictions are used to approximate key statistical descriptions of SN fatigue behavior. The approximated fatigue life distributions are validated against an experimentally found population of SN data at 10^4 and 10^6 cycles failure describing low cycle and high cycle fatigue. A Monte Carlo method is employed to model fatigue life by first modeling SN distributions at discrete stress amplitudes using the predicted fatigue life curves. Then the distributions are randomly sampled and a life prediction model is obtained. The approach is verified by using Aluminum 6061 data due to ample material characterization and previous life prediction analysis available in literature. SN life prediction is modeled via a Random Fatigue Limit (RFL) model using least square regression to determine the model coefficients. The life prediction framework is further developed by incorporating Bayesian statistical inference and stochastic sampling techniques to estimate the RFL model parameters. In addition, digital image correlation (DIC) is leveraged during experimentation to collect hysteresis energy as a novel method to monitor hysteresis strain energy or the assumed critical damage variable. Fatigue life prediction is performed in a dynamic way such that the life prediction model is continually updated with the generation of experimental data. The life prediction framework is applied to conventional Aluminum 6061-T6 and AM Inconel 718 and Titanium 6Al-4V. The framework is validated for life prediction and forecasting SN high cycle fatigue behavior using only low cycle fatigue data. The culmination of this work enables the rapid characterization of fatigue of AM materials by concurrently approximating the variation of fatigue life as well as high cycle fatigue behavior with low cycle fatigue data. The benefit of this framework is the significant reduction in experimental testing time, effort, and cost necessary to accurately assess the fatigue behavior of materials with limited prior information and specimen availability, such as in the case with AM Alloys.

Author: Yung-Li Lee
Publisher: Elsevier
ISBN: 0080477690
Category : Technology & Engineering
Languages : en
Pages : 417

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Book Description
Fatigue Testing and Analysis: Theory and Practice presents the latest, proven techniques for fatigue data acquisition, data analysis, and test planning and practice. More specifically, it covers the most comprehensive methods to capture the component load, to characterize the scatter of product fatigue resistance and loading, to perform the fatigue damage assessment of a product, and to develop an accelerated life test plan for reliability target demonstration. This book is most useful for test and design engineers in the ground vehicle industry. Fatigue Testing and Analysis introduces the methods to account for variability of loads and statistical fatigue properties that are useful for further probabilistic fatigue analysis. The text incorporates and demonstrates approaches that account for randomness of loading and materials, and covers the applications and demonstrations of both linear and double-linear damage rules. The reader will benefit from summaries of load transducer designs and data acquisition techniques, applications of both linear and non-linear damage rules and methods, and techniques to determine the statistical fatigue properties for the nominal stress-life and the local strain-life methods. - Covers the useful techniques for component load measurement and data acquisition, fatigue properties determination, fatigue analysis, and accelerated life test criteria development, and, most importantly, test plans for reliability demonstrations - Written from a practical point of view, based on the authors' industrial and academic experience in automotive engineering design - Extensive practical examples are used to illustrate the main concepts in all chapters

Author: Claude Amzallag
Publisher: ASTM International
ISBN:
Category :
Languages : en
Pages : 658

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Author: Anastasios P. Vassilopoulos
Publisher: Woodhead Publishing
ISBN: 0081025769
Category : Technology & Engineering
Languages : en
Pages : 766

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Book Description
Fatigue Life Prediction of Composites and Composite Structures, Second Edition, is a comprehensive review of fatigue damage and fatigue life modeling and prediction methodologies for composites and their use in practice. In this new edition, existing chapters are fully updated, while new chapters are introduced to cover the most recent developments in the field. The use of composites is growing in structural applications in many industries, including aerospace, marine, wind turbine and civil engineering. However, there are uncertainties about their long-term performance, including performance issues relating to cyclic fatigue loading that hinder the adoption of a commonly accepted credible fatigue design methodology for the life prediction of composite engineering structures. With its distinguished editor and international team of contributors, this book is a standard reference for industry professionals and researchers alike. - Examines past, present and future trends associated with the fatigue life prediction of composite materials and structures - Assesses novel computational methods for fatigue life modeling and prediction of composite materials under constant amplitude loading - Covers a wide range of techniques for predicting fatigue, including their theoretical background and practical applications - Addresses new topics and covers contemporary research developments in the field

Author: Xiangqiao Yan
Publisher: CRC Press
ISBN: 1000830314
Category : Mathematics
Languages : en
Pages : 368

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This book presents the unified fatigue life prediction equation for low/medium/high cycle fatigue of metallic materials relevant to plain materials and notched components. The unified fatigue life prediction equation is the Wöhler equation, in which the "stress-based intensity parameter" is calculated based on the linear-elastic analysis. A local approach for the static fracture analysis for notched components is presented based on the notch linear-elastic stress field. In the local approach, a stress intensity parameter is taken as a stress-based intensity parameter. Experimental verifications show that the local approach is also suited for the static fracture analysis for notched components made of ductile materials. The book is also concerned with a material failure problem under the multiaxial stress states. A concept of the material intensity parameter is introduced in this book. It is a material property parameter that depends on both Mode-I fracture toughness and Mode-II (or Mode-III) fracture toughness and the multiaxial parameter to characterize the variation of the material failure resistance (notch fracture toughness) with the multiaxial stresses states. The failure condition to assess mixed-mode fracture of notched (or cracked) components is stated as the stress-based intensity parameter being equal to the material intensity parameter. With respect to the traditional S-N equation, a similar S-N equation is presented and verified to have high accuracy. This book will be of interest to professionals in the field of fatigue and fracture for both brittle and ductile materials.

Author: Michael R. Mitchell
Publisher: ASTM International
ISBN: 080312029X
Category : Fracture mechanics
Languages : en
Pages : 354

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