NUMERICAL MODELLING OF IMPACT ON 3D COMPOSITE STRUCTURES (original) (raw)
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Investigation of impact and damage tolerance in advanced aerospace composite structures
International Journal of Crashworthiness - INT J CRASHWORTHINESS, 2003
NOTATION α = Non-linear shear strain parameter σ 11 = Stress in the fibre direction σ 12 = In-plane shear stress σ 22 = Stress in the direction normal to the fibres G 12 = In-plane shear modulus S = Allowable in-plane shear strength S T = Allowable transverse shear strength X T = Allowable fibre tension strength X C = Allowable fibre compression strength Y T = Allowable matrix tension strength Y C = Allowable matrix compression strength Abstract: With the aim of gaining a better understanding of the non-linear behaviour of advanced aerospace composite structures under dynamic loadings, this paper provides an overview of the state of the available analysis tools and reports on the progress of an investigation designed to study the low velocity impact characteristics of such structures. The paper further details the experimental set up and procedures of a drop weight impact test system and the equipment used as well as the specifications of its online data acquisition system. In conclusion, as an indicative verification of the ongoing work, a brief comparison of the test results with the numerical data, obtained from a simulation of the test in a number of explicit non-linear finite element environments, is provided.
Le Journal de Physique IV, 1997
The aim of this paper is to present a method for taking into account, in numerical terms, the physics of damage events during impact of composite structures. The modeling of damage phenomena is based on the following choices : the use of an averaging model and a contact technique, and simple criteria to define the numerical conditions of initiation and extension of damage events. This approach is applied here to numerical modeling of the impact of ten plies symmetrical glass-epoxy 0190 laminated plates where matrix cracking controls delamination and hence considered of primary importance.
Design Allowable Considerations for use of Laminated Composites in Aircraft Structures
| Carbon fibre polymer composites have evolved over the years to become major structural materials for primary structures of the aircraft today. The paper reviews the work carried out over last four decades on carbon fiber polymer composites to create an understanding of their behaviour in order to set up a philosophy of design and arriving at design allowable values for strength so as to ensure safety and performance of aircraft with minimum weight penalty. The rationale behind the choice of allowable values and the process to arrive at them is explained. While several issues are discussed, three major aspects are emphasised: the environmental (hygrothermal) effect, the effect of holes and fasteners and impact damage. The directions of the current improvements and course of future developments are indicated in relation to their influence on the design allowables.
On behalf of: American Society for Composites
Damage development due to impact needs to be understood to evaluate the consequences of impact on composite structures. This study concentrates on modelling and measuring damage development due to low velocity impact on thick industrial composites made from glass fibre epoxy by vacuum-assisted resin infusion. Cross-plied laminates were tested with different impact energy and different number of interfaces (clustering). Results were compared to a 3D finite element analysis. Interfaces and their damage development were modelled with cohesive elements. Intra ply properties were modelled by progressive failure analysis. Many elements and large memory use were needed to obtain sufficient modelling accuracy. However, all input parameters of the model were based on widely available and independently obtained material properties. Impact force and time to initiate damage and maximum force were measured and related to impact energy and clustering. Damage development was monitored optically in the translucent material for all test cases. The results show that the numerical model using only simple and independently measured material data was able to predict the impact behaviour for the different energies and different stacking sequences.
Finite element analysis of composites materials for aerospace applications
IOP Conference …, 2010
Composites materials are intended to be used more extensively as an alternative of aluminum structure in aircraft and aerospace applications. This is due to their attractive properties as high strength-to-weight ratio and stiffness-to-weight ratio. Besides that it clarifies the growing interest for composites materials due to advantages of lightweight, high strength, high stiffness, superior fatigue life, tremendous corrosion resistance and low cost manufacturing. In this study, a finite element analysis (FEA) of fiberglass unidirectional Etype was analyzed in the framework of ABAQUS finite element commercial software. The analysis was done to quantify the mechanical properties and response of unidirectional E-glass in term of tensile, compression and thermal responses. From the analysis, the maximum and minimum values of stress and strain for E-glass 21xK43 Gevetex and Silenka E-glass 1200tex were obtained and stress-strain curve is presented. The ultimate load of failure, elastic behavior, tensile strength and other properties for each laminated plates under tensile and thermal-stress are determined from stress-strain curves. The simulation will run twice for each material where the first simulation based on orientation angles of 45° for ply-1, -45° for ply-2 and 90° for ply-3 while the second simulation, the orientation angles is 0° for all plies. The simulation is successfully conducted and verified by experimental data.
Of Impact Damages Modelling in Laminated Composite Aircraft Structures
2013
Preliminary notes Laminated composites have an important application in modern aeronautical structures. They have extraordinary properties, like high strength, stiffness and lightweight. Nevertheless, a serious obstacle to more widespread use of those materials is their sensitivity to impact loads. As a consequence of that, impact damage initiation and growth are appearing in them. Failures that occur in laminated composite structures can be intralaminar and interlaminar. To date a lot of models for impact damages in laminates have been developed with higher or lower accuracy. Those models can replace real and expensive testing in laminated structures with some approximation. By using specialized software the damage parameters in laminate aircraft structures can be predicted (at certain conditions). In that way numerical simulation of impact on certain laminates can be done and the obtained results from the simulations presented in a form of graphic damage distributions.
Review of impact damages modelling in laminated composite aircraft structures
Tehnicki Vjesnik-technical Gazette, 2013
Preliminary notes Laminated composites have an important application in modern aeronautical structures. They have extraordinary properties, like high strength, stiffness and lightweight. Nevertheless, a serious obstacle to more widespread use of those materials is their sensitivity to impact loads. As a consequence of that, impact damage initiation and growth are appearing in them. Failures that occur in laminated composite structures can be intralaminar and interlaminar. To date a lot of models for impact damages in laminates have been developed with higher or lower accuracy. Those models can replace real and expensive testing in laminated structures with some approximation. By using specialized software the damage parameters in laminate aircraft structures can be predicted (at certain conditions). In that way numerical simulation of impact on certain laminates can be done and the obtained results from the simulations presented in a form of graphic damage distributions.