Analysis of process-induced distortions and residual stresses of composite structures

Analysis of process-induced distortions and residual stresses of composite structures
Author: Christian Brauner
Publisher: Logos Verlag Berlin GmbH
Total Pages: 168
Release: 2013
Genre: Science
ISBN: 3832535284

The increased application of composite materials in lightweight structures leads to new integral design of structural parts, using the example of, an integral composite landing flap of an Airbus A320 aircraft. This offers possibilities to simplify the process chain, to decrease manufacturing costs and to have fibre fair structural design. The critical disadvantage of large integral designs is that process-induced deformations are a risk factor during the design phase of the manufacturing process, because rework is not always possible. Especially, the aircraft industry with its demands on high qualities / tolerances and the application of hot curing resin systems, requires knowledge-based methods for virtual process design to avoid time- and effort-consuming iterations. This thesis contributes to the understanding of the mechanism behind process-induced distortions and stresses related to the Resin Transfer Moulding (RTM) manufacturing process. The aim is to comprehend the phenomena, to identify related parameters and to present compensation strategies.

Numerical prediction of curing and process-induced distortion of composite structures

Numerical prediction of curing and process-induced distortion of composite structures
Author: Bernath, Alexander
Publisher: KIT Scientific Publishing
Total Pages: 294
Release: 2021-10-29
Genre: Technology & Engineering
ISBN: 3731510634

Fiber-reinforced materials offer a huge potential for lightweight design of load-bearing structures. However, high-volume production of such parts is still a challenge in terms of cost efficiency and competitiveness. Numerical process simulation can be used to analyze underlying mechanisms and to find a suitable process design. In this study, the curing process of the resin is investigated with regard to its influence on RTM mold filling and process-induced distortion.

Modeling Methods for Process Induced Distortions of CFRP-Parts produced in the Prepreg-Autoclave-Process

Modeling Methods for Process Induced Distortions of CFRP-Parts produced in the Prepreg-Autoclave-Process
Author: Tim Frerich
Publisher: Logos Verlag Berlin GmbH
Total Pages: 190
Release: 2023-06-20
Genre: Technology & Engineering
ISBN: 3832556435

Process induced distortions are a challenge in the production of high-performance components made of carbon fiber reinforced plastics. In order to prevent the distortions, a prediction is of great utility. For components manufactured in the prepreg autoclave process, which is often used in the aerospace industry, prediction methods are investigated within this work. First, the state of the art is discussed and, based on this, two promising approaches are identified, which are further investigated and implemented: A rapid simulation approach and a complex one, which requires more effort but allows further investigations of the distortions. For the latter approach, new material models and rules of mixture are developed that take into account modern material architectures with interleaf layers. Using these material models, the observed material behavior can be represented more accurately than with material models from the literature. The results obtained by both approaches are compared with experimental results. A good agreement can be shown between the measurements and the simulation.

Residual Stresses in Composite Materials

Residual Stresses in Composite Materials
Author: Mahmood M. Shokrieh
Publisher: Woodhead Publishing
Total Pages: 407
Release: 2014-02-14
Genre: Technology & Engineering
ISBN: 0857098594

Residual stresses are a common phenomenon in composite materials. They can either add to or significantly reduce material strength. Because of the increasing demand for high-strength, light-weight materials such as composites and their wide range of applications in the aerospace and automotive industries, in civil infrastructure and in sporting applications, it is critical that the residual stresses of composite materials are understood and measured correctly. The first part of this important book reviews destructive and non-destructive testing (NDT) techniques for measuring residual stresses. Various mathematical (analytical and numerical) methods for calculation of residual stresses in composite materials are also presented. Chapters in the first section of the book discuss the simulated hole drilling method, the slitting/crack compliance method, measuring residual stresses in homogeneous and composite glass materials using photoelastic techniques, and modeling residual stresses in composite materials. The second part of the book discusses residual stresses in polymer matrix, metal-matrix and a range of other types of composites. Moreover, the addition of nanoparticles to the matrix of polymeric composites as a new technique for reduction of residual stresses is discussed. Residual stresses in composite materials provides a comprehensive overview of this important topic, and is an invaluable reference text for both academics and professionals working in the mechanical engineering, civil engineering, aerospace, automotive, marine and sporting industries. Reviews destructive and non-destructive testing (NDT) techniques for measuring residual stresses Discusses residual stresses in polymer matrix, metal-matrix and other types of composite Considers the addition of nanoparticles to the matrix of polymeric composites as a new technique for reduction of residual stresses

Structural Health Monitoring For Advanced Composite Structures

Structural Health Monitoring For Advanced Composite Structures
Author: M H Ferri Aliabadi
Publisher: World Scientific
Total Pages: 286
Release: 2017-12-18
Genre: Technology & Engineering
ISBN: 1786343940

Structural health monitoring (SHM) is a relatively new and alternative way of non-destructive inspection (NDI). It is the process of implementing a damage detection and characterization strategy for composite structures. The basis of SHM is the application of permanent fixed sensors on a structure, combined with minimum manual intervention to monitor its structural integrity. These sensors detect changes to the material and/or geometric properties of a structural system, including changes to the boundary conditions and system connectivity, which adversely affect the system's performance.This book's primary focus is on the diagnostics element of SHM, namely damage detection in composite structures. The techniques covered include the use of Piezoelectric transducers for active and passive Ultrasonics guided waves and electromechanical impedance measurements, and fiber optic sensors for strain sensing. It also includes numerical modeling of wave propagation in composite structures. Contributed chapters written by leading researchers in the field describe each of these techniques, making it a key text for researchers and NDI practitioners as well as postgraduate students in a number of specialties including materials, aerospace, mechanical and computational engineering.

Damage and Failure of Composite Materials

Damage and Failure of Composite Materials
Author: Ramesh Talreja
Publisher: Cambridge University Press
Total Pages: 315
Release: 2012-06-07
Genre: Science
ISBN: 0521819423

Bringing together materials mechanics and modelling, this book provides a complete guide to damage mechanics of composite materials for engineers.

Defects and Damage in Composite Materials and Structures

Defects and Damage in Composite Materials and Structures
Author: Rikard Benton Heslehurst
Publisher: CRC Press
Total Pages: 216
Release: 2014-04-21
Genre: Technology & Engineering
ISBN: 146658047X

The advantages of composite materials include a high specific strength and stiffness, formability, and a comparative resistance to fatigue cracking and corrosion. However, not forsaking these advantages, composite materials are prone to a wide range of defects and damage that can significantly reduce the residual strength and stiffness of a structure or result in unfavorable load paths. Emphasizing defect identification and restitution, Defects and Damage in Composite Materials and Structures explains how defects and damage in composite materials and structures impact composite component performance. Providing ready access to an extensive, descriptive list of defects and damage types, this must-have reference: Examines defect criticality in composite structures Recommends repair actions to restore structural integrity Discusses failure modes and mechanisms of composites due to defects Reviews NDI processes for finding and identifying defects in composite materials Relating defect detection methods to defect type, the author merges his experience in the field of in-service activities for composite airframe maintenance and repair with indispensable reports and articles on defects and damage in advanced composite materials from the last 50 years.

Composites Manufacturing

Composites Manufacturing
Author: Sanjay Mazumdar
Publisher: CRC Press
Total Pages: 417
Release: 2001-12-27
Genre: Technology & Engineering
ISBN: 1420041983

More and more companies manufacture reinforced composite products. To meet the market need, researchers and industries are developing manufacturing methods without a reference that thoroughly covers the manufacturing guidelines. Composites Manufacturing: Materials, Product, and Process Engineering fills this void. The author presents a fundamental