Axial and Lateral Impact Prediction of Composite Structures Using Explicit Finite Element Analysis

2002 ◽  
Author(s):  
Ari G. Caliskan
Keyword(s):  
Composite Materials ◽  
Composite Structures ◽  
Impact Analysis ◽  
Failure Modes ◽  
Basic Material ◽  
Lateral Impact ◽  
Absorption Mechanism ◽  
Element Analysis ◽  
Plane Shear ◽  
Structural Applications

The use of composite materials in the automotive industry is growing since these materials exhibit high stiffness, strength and low weight. As such, analytical capabilities must be developed in order for these materials to be used in more structural applications. Previous work in the area of crush performance has concentrated on experimental and empirical studies that have qualitatively characterized the crush process. These studies have shown that the crush process in composite materials is complex, and is dominated by fiber/matrix microcracking, which is the main energy absorption mechanism. In this study, the crush performance of a set of tubular composite structures were modeled using the explicit code RADIOSS™. Unlike many of the other commercially available codes, the composite material model within RADIOSS uses material input parameters that can be easily extracted from basic material test. These tests would include a 0° and 90° tensile and compressive test, as well as an in-plane shear test. The model can also accommodate strain rate effects. As the structure is loaded, the stresses within each element and ply are calculated. Using a Tsai-Wu failure criterion, the material fracture is simulated by removing a failed ply within a given element. As a consequence, the material degradation within and ahead of the crush front is simulated. The results of the study showed that the steady state crush load could be predicted accurately. However, the exact failure mode with the crushed structure was not as accurately represented in the model. In addition, two other case studies one being a 3-point bending on a hexagonal section and composite sandwich plate impact analysis were also performed. The results showed good agreement with experiments in both load levels and failure modes.

Review of material test standardization status for the material qualification of laminated thermosetting composite structures

2020 ◽  
pp. 073168442095810
Author(s):  
Sang Yoon Park ◽  
Won Jong Choi
Keyword(s):  
Composite Materials ◽  
Material Properties ◽  
Composite Structures ◽  
Failure Modes ◽  
Laminated Composite ◽  
Test Methods ◽  
Test Method ◽  
Experimental Comparison ◽  
Laminated Composite Materials ◽  
Design Values

This paper presents a review of recent literature related to the static mechanical testing of thermoset-based carbon fiber reinforced composites and introduces a material qualification methodology to generate statistically-based allowable design values for aerospace application. Although most test methods have been found to be effective in determining the specific material properties by incorporating them into the material qualification and quality control provisions, a full validation to clarify the behavior of thermoset-based laminated composite materials is currently lacking, particularly with regard to the characterization of compressive, in-plane, interlaminar shear, and damage tolerance properties. The present study obtains information on the different types of test method that can be employed within the same material properties, and makes an in-depth experimental comparison based on the past literatures. A discussion on the scope of theoretical analysis involves a description of how the proposed test method can be adequate for obtaining more accurate material properties. This discussion is directly applicable to the assessment of material nonlinearity and the geometrical effect of specimens. Finally, the resulting failure modes and the effect of each material property are studied to aid the understanding of the load distribution and behavior of laminated composite materials.

scholarly journals An Energy-Based Concept for Yielding of Multidirectional FRP Composite Structures Using a Mesoscale Lamina Damage Model

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 157 ◽  
Author(s):  
Seyed Rahimian Koloor ◽  
Atefeh Karimzadeh ◽  
Noorfaizal Yidris ◽  
Michal Petrů ◽  
Majid Ayatollahi ◽  
...  
Keyword(s):  
Yield Point ◽  
Composite Structures ◽  
Failure Modes ◽  
Initial Slope ◽  
Dissipation Energy ◽  
Fiber Failure ◽  
Damage Initiation ◽  
Frp Composite ◽  
Structural Applications ◽  
Evolution Curve

Composite structures are made of multidirectional (MD) fiber-reinforced polymer (FRP) composite laminates, which fail due to multiple damages in matrix, interface, and fiber constituents at different scales. The yield point of a unidirectional FRP composite is assumed as the lamina strength limit representing the damage initiation phenomena, while yielding of MD composites in structural applications are not quantified due to the complexity of the sequence of damage evolutions in different laminas dependent on their angle and specification. This paper proposes a new method to identify the yield point of MD composite structures based on the evolution of the damage dissipation energy (DDE). Such a characteristic evolution curve is computed using a validated finite element model with a mesoscale damage-based constitutive model that accounts for different matrix and fiber failure modes in angle lamina. The yield point of composite structures is identified to correspond to a 5% increase in the initial slope of the DDE evolution curve. The yield points of three antisymmetric MD FRP composite structures under flexural loading conditions are established based on Hashin unidirectional (UD) criteria and the energy-based criterion. It is shown that the new energy concept provides a significantly larger safe limit of yield for MD composite structures compared to UD criteria, in which the accumulation of energy dissipated due to all damage modes is less than 5% of the fracture energy required for the structural rupture.

scholarly journals An Optimization Tool for Impact Analysis of Composite Structures

2018 ◽  
Author(s):  
DC Pham
Keyword(s):  
Impact Loading ◽  
Composite Structures ◽  
Impact Analysis ◽  
Failure Modes ◽  
Drop Test ◽  
Matrix Cracking ◽  
Computational Time ◽  
Failure Behavior ◽  
Test Analysis ◽  
Plane Failure

Composite materials exhibit complex failure behavior under impact loading especially such as that for composite landing gear structure. Possible failure modes in composites may include matrix cracking, fiber breakage, kinking, fiber-matrix debonding or delamination between composite plies. In order to better understand the damage mechanisms and non-linear response of composite structures under impact, complex geometries, materials, ply orientations and stacking sequence need to be considered. However, general drop test analysis for composite structures usually takes a lot of computational efforts, and it may be even more expensive for failure analysis and optimization when various structural geometries and design configurations are taken into account. This paper proposes a new methodology for evaluation and optimization of failure behavior of composite structures subjected to impact loading, whereby drop test analysis of composite structures is modeled by explicitly dynamics analysis of two-dimensional structures and implicit analysis of three-dimensional solid structures to predict delamination or out-of-plane failure. The above-mentioned modeling strategy helps speed up the optimization process and considerably save computational time and efforts. The proposed methodology together with reliable optimization algorithms and failure theory criteria are integrated and coded into a FE optimization tool by Python script. It is shown that the optimization tool effectively helps engineers and researchers perform optimization of general composite structures and fully take into account of various geometries, materials, loading configurations, composite stack-up and sequences and individual ply's orientation.

scholarly journals Numerical Modelling of Glass Fiber Reinforced Polymer (GFRP) Cross Arm

2019 ◽  
Vol 8 (4) ◽  
pp. 6484-6489
Keyword(s):  
Failure Modes ◽  
Limit State ◽  
Geometrical Model ◽  
Fiber Direction ◽  
Ultimate Limit State ◽  
Element Analysis ◽  
Plane Shear ◽  
Glass Fiber Reinforced ◽  
Out Of Plane ◽  
The Matrix

Composites are not isotropic like their metal counterparts, e.g. steel and aluminum, as they are made of two distinctive phases known as the matrix and the reinforcing phases. In addition, weight, fiber direction, fiber composition and even the manufacturing process are all critical factors in determining the strength, stiffness and the behaviour of a composite member. All of that create more challenging designing and manufacturing approaches. This paper shows how to model a GFRP cross arm using SOLIDWORKS to create the 3D geometrical model because it has an intuitive and easy to use user interface, and ANSYS to create the numerical model and the analysis for its great and comprehensive capabilities in the finite element analysis. The cross arm was found to be safe against the failure modes of fiber, matrix, in-plane shear, out-of-plane shear and delamination under all load cases which satisfies the ultimate limit state requirements but the concern was on the serviceability limit state which had a deflection of 34 mm.

A Review of Damage Tolerant Design, Certification and Repair in Metals Compared to Composite Materials

2014 ◽  
Vol 891-892 ◽  
pp. 1597-1602 ◽  
Author(s):  
Nabil Chowdhury ◽  
Wing Kong Chiu ◽  
John Wang
Keyword(s):  
Composite Materials ◽  
Composite Structures ◽  
Failure Modes ◽  
Structural Integrity ◽  
Fiber Reinforced Polymers ◽  
Carbon Fiber Reinforced Polymers ◽  
Reinforced Polymers ◽  
Repair Efficiency ◽  
Mechanically Fastened ◽  
Damage Tolerant

A review of some of the various fatigue models introduced over the years for both metallic materials, in particular aluminium alloys followed by fatigue and durability concerns associated with composite materials. The move towards light weight and high stiffness structures that have good fatigue durability and corrosion resistance has led to the rapid move from metal structures to composite structures. With this brings the added concern of certifying new components as the damage mechanisms and failure modes in metals differ significantly than composite materials such as carbon fiber reinforced polymers (CFRP). The certification philosophy for composites must meet the same structural integrity, safety and durability requirements as that of metals. Hence this is where the challenge now lies. Substantial work has been conducted in the reparability of composite structures through bonding using various adherend thicknesses and joint types and has been shown to have higher durability than mechanically fastened repairs for thin adherends however these are currently unacceptable repair methods as they cannot be certified. Repairs are designed on the basis that the repair efficiency can be predicted and should be designed conservatively with respect to the various failure modes and include the surrounding structure.

Acoustic Emission and Ultrasound Phased Array Technique for Composite Material Evaluation

2013 ◽  
Author(s):  
Hossein Taheri ◽  
Fereidoon Delfanian ◽  
Jikai Du
Keyword(s):  
Acoustic Emission ◽  
Composite Materials ◽  
Composite Structures ◽  
Phased Array ◽  
Failure Modes ◽  
Acoustic Energy ◽  
Single Element ◽  
Signal Velocity ◽  
Acoustic Evaluation ◽  
Conventional Ultrasound

The successful application of various acoustic evaluation techniques to composite materials and structures depends on the understanding of the acoustic wave propagation mechanisms. However, due to the anisotropic nature of composite materials, where the acoustic signal velocity and attenuation depend on its traveling direction, the correlation of the different material failure modes to the recorded acoustic signals, such as during of an acoustic emission (AE) inspection, is difficult to be defined. This issue becomes even more challenging for ultrasound phased array technique, where unlike a conventional ultrasound single element transducer, an ultrasound phased array of sensors will generate and receive acoustic energy at various desired directions and locations. Such heightened flexibility and sensitivity is essential for the complex shape of modern composite structures. In this paper, the influence of fiber orientation on AE signal was first studied. AE parameters such as counts, duration, energy, rise time and amplitude for aluminum and composite plate were analyzed in MS-Excel and results were compared to AE software. Acoustic velocities along various fiber directions were also theoretically studied and experimentally measured. Then ultrasound phased array technique and related parameters such as ultrasound beam angle and focusing, frequency and material attenuation factors were quantitatively analyzed, and the optimization and limitation of ultrasound phased array inspection procedure were summarized.

Low Velocity Impact Analysis on GFRP Laminates under Different Temperatures

2011 ◽  
Vol 110-116 ◽  
pp. 632-636
Author(s):  
K. Pazhanivel ◽  
G.B. Bhaskar ◽  
S. Arunachalam ◽  
V. Hariharan ◽  
A. Elayaperumal
Keyword(s):  
Composite Materials ◽  
Impact Analysis ◽  
Failure Modes ◽  
Laminated Composites ◽  
Low Velocity Impact ◽  
Impact Behavior ◽  
Low Velocity ◽  
Aerospace Applications ◽  
Different Temperatures ◽  
The Impact

Composite materials have a number of properties that make them attractive for use in aerospace applications. The impact behavior of fiber reinforced composite materials is much more complex than conventional metallic structures due to a number of different failure modes on the inter laminar and intra laminar level. The aim of this study is to investigate the effects of temperature and thermal residual stresses on the impact behavior and damage of glass/epoxy laminated composites. To this end, thermal stress analyses of the laminates with lay-ups [90/0/0/90] s, [90/0/45/45] s, [0/90/45/-45] s, [45/0/-45/90] s are carried out under different temperatures by using ANSYS software. Also, the impact analysis on the laminated composites was performed at the different range of impact energies under different temperatures. The specific energy values and impact parameters were obtained and compared for each type of specimens and temperatures.

scholarly journals Study on Mechanical Bearing Strength and Failure Modes of Composite Materials for Marine Structures

2021 ◽  
Vol 9 (7) ◽  
pp. 726
Author(s):  
Dong-Uk Kim ◽  
Hyoung-Seock Seo ◽  
Ho-Yun Jang
Keyword(s):  
Composite Materials ◽  
Failure Mode ◽  
Composite Structures ◽  
Failure Modes ◽  
Offshore Structures ◽  
Fiber Reinforced ◽  
Bearing Strength ◽  
Fiber Reinforced Plastic ◽  
Reinforced Plastic ◽  
Mechanically Fastened

With the gradual application of composite materials to ships and offshore structures, the structural strength of composites that can replace steel should be explored. In this study, the mechanical bearing strength and failure modes of a composite-to-metal joining structure connected by mechanically fastened joints were experimentally analyzed. The effects of the fiber tensile strength and stress concentration on the static bearing strength and failure modes of the composite structures were investigated. For the experiment, quasi-isotropic [45°/0°/–45°/90°]2S carbon fiber-reinforced plastic (CFRP) and glass fiber-reinforced plastic (GFRP) specimens were prepared with hole diameters of 5, 6, 8, and 10 mm. The experimental results showed that the average static bearing strength of the CFRP specimen was 30% or higher than that of the GFRP specimen. In terms of the failure mode of the mechanically fastened joint, a cleavage failure mode was observed in the GFRP specimen for hole diameters of 5 mm and 6 mm, whereas a net-tension failure mode was observed for hole diameters of 8 mm and 10 mm. Bearing failure occurred in the CFRP specimens.

scholarly journals An Experimental and Numerical Study of Repairs on Composite Substrates with Composite and Aluminum Doublers Using Riveted, Bonded, and Hybrid Joints

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2978 ◽  
Author(s):  
Pitta ◽  
Roure ◽  
Crespo ◽  
Rojas
Keyword(s):  
Composite Structures ◽  
Failure Modes ◽  
Numerical Study ◽  
Progressive Failure ◽  
Adhesive Bond ◽  
Element Analysis ◽  
Fea Model ◽  
Composite Substrate ◽  
Riveted Joints ◽  
Hybrid Joints

In this work, experimental and numerical analyses of repairs on carbon fiber reinforced epoxy (CFRE) substrates, with CFRE and aluminum alloy doublers typical of aircraft structures, are presented. The substrates have a bridge gap of 12.7 mm (simulated crack), repaired with twin doublers joined with riveted, adhesive bonded, and hybrid joints. The performance of the repairs using different doubler materials and joining techniques are compared under static loading. The experimental results show that riveted joints have the lowest strength, while adhesive bonded joints have the highest strength, irrespective of the doubler material. Finite element analysis (FEA) of the studied joints is also performed using commercial FEA tool Abaqus. In the FEA model, point-based fasteners are used for the rivets, and a cohesive zone contact model is used to simulate the adhesive bond. The FEA results indicate that the riveted joints have higher tensile stresses on the metal doublers compared to the composite doublers. As per the failure modes, interestingly, for hybrid joints using composite doublers, the doublers fail due to net-section failure, while, for hybrid joints using metal doublers, it is the composite substrate that fails due to net-section failure. This suggests vulnerability of the composite structures to mechanical fastener holes. Lastly, the Autodesk Helius composite tool is used for prediction of first-ply failure and ply load distribution, and for progressive failure analysis of the composite substrate.

scholarly journals A Computer-Aided Analysis System With DBMS Support for Fiber-Reinforced Thick Composite Materials

1991 ◽  
Author(s):  
Lisa K. Spainhour ◽  
William J. Rasdorf ◽  
Edward M. Patton ◽  
Bruce P. Burns ◽  
Craig S. Collier
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Composite Materials ◽  
Composite Structures ◽  
Data Transfer ◽  
Element Analysis ◽  
Materials Database ◽  
Computer Aided Analysis ◽  
Computer Aided ◽  
Analysis System

Abstract The broad scope of the research described herein is the integration of several components of engineering software using a relational database. More specifically, a conceptual finite element material preprocessing system for fiber-reinforced composite materials was studied. In this computer-aided analysis (CAA) system, a materials database is integrated with several software components, including commercially available finite element analysis (FEA) programs and preprocessors, and tools for the design of laminated composite materials. The focus of the system is on the integration of two- and three-dimensional composite materials data into several finite element analysis programs. Particular attention is given to analysis and design of components and structures using thick composite materials. Many engineering applications exist for thick composite structures; however, they have received less critical attention than the thin composite structures often used in aerospace applications. The primary objective of the composites analysis system is to enhance data transfer between and interaction among several engineering software programs with a minimum of user interaction. This paper describes a specific implementation of a computer-aided analysis system that achieves this objective, detailing the need for the system and describing each of its components, including a composite materials database. The capabilities of the integrated system are discussed, including tasks such as composite laminate design, data entry, report generation, and interface file generation, performed in support of the finite element analysis capability. A major focus of the paper is on the twofold role of the materials database in the analysis system, as both a passive data repository and as a dynamic data transfer mechanism. The use of interface programs and direct integration techniques are discussed in the context of passing materials data between the user and the database, and between the database and the various system components or application programs.

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