597 research outputs found
Creep/fatigue/relaxation of angle-ply GFRP composite laminates
No full textFiber-reinforced polymer (FRP) composites are used in engineering structures of several domains, such as wind energy, bridges, and automotive industry. Usually such material systems include polymeric matrices and exhibit behavior that is sensitive to the loading pattern due to their cyclic- and time-dependent mechanical properties. Although the majority of the aforementioned engineering applications undergoes a significant number of fatigue cycles, of random loading profiles, throughout their lifetime, the research efforts assigned to the investigation of the loading effects on their fatigue behavior are still very limited. Fatigue design allowables are today derived from standardized experimental investigations, mainly subjecting the examined materials under constant amplitude continuous fatigue loading; not corresponding to actual loading profiles seen by the structures in open air applications. This chapter aims to present the effect of different loading patterns on the fatigue life and damage development of angle-ply thermoset composites, discussing the influence of load interruptions including periods of zero load, when the material recovers, or periods of load hold times, during which the material creeps.CCLA
Fatigue life modeling and prediction methods for composite materials and structures—Past, present, and future prospects
No full textThis chapter aims to provide an overview of the fatigue life modeling and prediction methods for composite materials and structures, recalling methods used in the past, discovering the present status, and attempting to foresee future trends.CCLA
Fatigue life prediction of composites and composite structures - second edition
No full textFatigue 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.CCLA
Proceedings of the 20th European Conference on Composite Materials - Composites Meet Sustainability (Vol 1-6)
No full textThis collection gathers all the articles that were submitted and presented at the 20th European Conference on Composite Materials (ECCM20) which took place in Lausanne, Switzerland, June 26-30,2022. ECCM20 is the 20th edition of a conference series having its roots back in time, organized each two years by members of the European Society of Composite Materials (ESCM). The ECCM20 event was organized by the Composite Construction laboratory (CCLab) and the Laboratory for Processing of Advanced Composites (LPAC) of the Ecole Polytechnique Fédérale de Lausanne (EPFL). The Conference Theme this year was “Composites meet Sustainability”. As a result, even if all topics related to composite processing, properties and applications have been covered, sustainability aspects were highlighted with specific lectures, roundtables and sessions on a range of topics, from bio-based composites to energy efficiency in materials production and use phases, as well as end-of-life scenarios and recycling. More than 1000 participants shared their recent research results and participated to fruitful discussions during the five conference days, while they contributed more than 850 papers which form the six volumes of the conference proceedings. Each volume gathers contributions on specific topics : Vol 1 – Materials Vol 2 – Manufacturing Vol 3 – Characterization Vol 4 – Modeling and Prediction Vol 5 – Applications and Structures Vol 6 – Life Cycle Assessment We enjoyed the event; we had the chance to meet each other in person again, shake hands, hold friendly talks, and maintain our long-lasting collaborations. We appreciated the high level of the research presented at the conference and the quality of the submissions that are now collected in these six volumes. We hope that everyone interested in the status of the European Composites’ research in 2022 will be fascinated by this publication.CCLABLPACThis is a six volume book of the proceedings All six volumes will have the same title and each will have a single subtitle: Vol 1: Materials Vol 2: Manufacturing Vol 3: Characterization Vol 4: Modeling and Prediction Vol 5: Applications and Structures Vol 6: Life Cycle Assessmen
Computational intelligence methods for the fatigue life modeling of composite materials
No full textNovel computational methods such as artificial neural networks, adaptive neuro-fuzzy inference systems and genetic programming are used in this chapter for the modeling of the nonlinear behavior of composite laminates subjected to constant amplitude loading. The examined computational methods are stochastic nonlinear regression tools, and can therefore be used to model the fatigue behavior of any material, provided that sufficient data are available for training. They are material independent methods that simply follow the trend of the available data, in each case giving the best estimate of their behavior. Application on a wide range of experimental data gathered after fatigue testing glass/epoxy and glass/polyester laminates proved that their modeling ability compares favorably with, and is to some extent superior to, other modeling techniques.CCLA
Fatigue life prediction under realistic loading conditions
No full textThe accurate modeling of the fatigue behavior of composite materials under constant amplitude (CA) cyclic stress is in itself a difficult task but when loading is of variable amplitude (VA), the situation is even more complicated since an appropriate damage metric and rules for its summation must be defined. One of the widely used approaches is based on the theoretical formulation and use of a damage summation rule to predict life under VA loading without recourse to experimental observation of the damage accumulation process. The most popular and best-known example of this category, which does not always lead to accurate results however, is the linear Palmgren-Miner rule. Other summation rules were also proposed as alternatives to the use of Palmgren-Miner rule to accurately predict the fatigue lifetime of glass-fiber reinforced plastic (GFRP) and CFRP composites loaded under block or VA loading patterns. An alternative to this classic fatigue life prediction methodology is the residual strength fatigue theories, where residual strength is used as the damage metric. Comparison of the remaining strength of the material to the static strength allows the estimation of the fatigue cycles until failure. The basic fatigue modeling introduced in previous chapters of this book for the interpretation of the fatigue data (Chapter 2), residual strength theories (Chapter 3), and constant life diagrams (Chapter 6) is combined here to establish fatigue life prediction methodologies.CCLA
On the fatigue behavior of thin and thick adhesively bonded composite joints
No full textInvestigations of the fatigue performance of adhesively bonded joints were initiated since the 1950 s. An abundance of publications has emerged dealing with the experimental investigation of the fatigue performance of adhesively bonded joints of various geometries and material combinations to serve the needs of various structures operating under various loading and environmental conditions. This work reviews the fatigue of composite adhesively bonded joints by analyzing relevant literature and reviewing current testing standards for primary applications. It classifies joints based on the materials used and the bondline thickness moving from thin film adhesive joints to thick paste adhesive joints to cover a wide range of contemporary engineering applications. The findings lead to a comprehensive discussion that lays the groundwork for further research in this field
Block and variable amplitude fatigue and fracture behavior of adhesively-bonded composite structural joints
No full textThe fatigue behavior of adhesively-bonded glass fiber-reinforced polymer (GFRP) joints is affected by the loading sequence. Analysis of several experimental data for composite materials and adhesively-bonded composite joints showed that the loading sequence effect is a function of the loading type, the applied loading levels and the material under investigation. Exhibited failure modes, related to the loading pattern, significantly affect the development of damage in adhesively-bonded composite joints. The aim of this chapter is to investigate the load sequence effect of both block and variable amplitude loading conditions on the fatigue behavior of adhesively-bonded pultruded GFRP joints.CCLA
Introduction to the fatigue life prediction of composite materials and structures: past, present and future prospects
No full textThis chapter aims to provide an overview of the fatigue life prediction methods for composite materials and structures, recalling methods used in the past, discovering the present status and attempting to foresee future trends.CCLA
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