scholarly journals The Impact Behaviour of Carbon Fiber-Epoxy Composite Leading Edge using Finite Element Method

2019 ◽  
Vol 8 (2) ◽  
pp. 2617-2622
Keyword(s):  
Finite Element ◽  
Weight Ratio ◽  
Leading Edge ◽  
High Strength ◽  
Failure Criteria ◽  
High Energy ◽  
Rigid Sphere ◽  
Impact Behaviour ◽  
Finite Element Software ◽  
The Impact

Composite material has been widely used in aircrafts due to its high strength to weight ratio that leads to weight saving of the aircrafts. Equally important, aircraft material should be tough i.e. it should have the ability to absorb high energy and thus resist fracture. The aircraft’s wing design requires the material to have high toughness as parts of the wing especially its leading edge is subjected to impact loadings. Using finite element software of LS-DYNA, this research focuses on studying the impact behaviour of composite panels that represent the leading edges of wings when the panels are subjected to rigid sphere projectile. Three shapes of panels are used: flat, semi-circular and semi ellipse while panels can be of 2, 4 and 8 layers to vary its thickness. The panels are made of laminated composites with woven carbon fibres and the angle of orientations are [0/90] n, [0/45]n and [45/-45]n where n will give the number of layer for the composite. The Mat-58 material type suitable for woven type fibre is used where failure criteria of Hashin is applied. It was found that the simulation results are in a very close agreement with the finding from experiments conducted earlier. Furthermore, the optimum stacking sequence was found to be the [0/45]2 stacking sequences

Validation of Macroscopic Forming Simulations of a Unidirectional Pre-Impregnated Material through Optical Measurements

2013 ◽  
Vol 554-557 ◽  
pp. 465-471 ◽  
Author(s):  
Alexane Margossian ◽  
François Dumont ◽  
Uwe Beier
Keyword(s):  
Finite Element ◽  
Carbon Fibre ◽  
Weight Ratio ◽  
High Strength ◽  
Element Model ◽  
Optical Measurements ◽  
Woven Fabric ◽  
Measuring System ◽  
Finite Element Software ◽  
Carbon Fibre Reinforced Plastic

Presenting interesting aspects such as a high strength-to-weight ratio, Carbon Fibre Reinforced Plastic components are frequently used in the aerospace industry. The forming step, which conforms the reinforcement to a specific geometry, is a sensitive phase of the manufacturing process. In order to detect the occurrence of defects prior to any trial, forming methods are often simulated via finite element software. The presented work will detail the simulation validation of a double curved helicopter frame forming out of a unidirectional carbon fibre pre-impregnated material (M21E, Hexcel®). The finite element model was based on an explicit approach at a macroscopic level and developed via the commercially available software Visual-Crash PAM (ESI®) [1]. The validation was carried out on six different preforms. Measurements of the top layers were performed by an enhanced version of a 4D measuring system, originally developed for non-woven fabric [2], able to make reproducible photographic and height measurements (Fig. 1). Experimental results were then compared to simulated ones. Due to material specificities, the photo quality reached for non-crimp fabrics could not be achieved [2]. After hardware and software modifications, measurements and analyses were eventually successfully completed. The validation of the simulation reached an accuracy of 1° to 3° depending on the geometrical features of the preform (Fig. 2).

Global Characterization of Failure Modes Under Impact Loading in Structural Components Made of Low Ductility Materials

2001 ◽  
Author(s):  
Shen Rong Wu ◽  
Xiaoming Chen ◽  
Weiran Hu
Keyword(s):  
Finite Element ◽  
Failure Modes ◽  
Failure Process ◽  
Failure Criteria ◽  
Tensile Failure ◽  
Forming Limit ◽  
Structural Components ◽  
Explicit Finite Element ◽  
Finite Element Software ◽  
The Impact

Abstract This study reviews the impact failure modes of structural components made of materials with low ductility such as aluminum and magnesium. Tensile failure is observed at large stretch area or on the tension side of large bending deformation. Material breakage due to shear may also occur. There are several approaches to simulate the material failure process in explicit finite element software used for crashworthiness analysis. Evaluation of the effective applications of these material models is presented with a finite element simulation of bi-axial loading tests. The forming limit diagram is used to evaluate various failure criteria. Component crash simulations are presented to demonstrate the applications of failure criteria.

scholarly journals Ultrahigh Ballistic Resistance of Twisted Bilayer Graphene

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 206
Author(s):  
Qing Peng ◽  
Sheng Peng ◽  
Qiang Cao
Keyword(s):  
Weight Ratio ◽  
High Strength ◽  
Bilayer Graphene ◽  
Energy Propagation ◽  
Dynamic Simulations ◽  
Protective Material ◽  
Impact Performance ◽  
Ballistic Resistance ◽  
Twisted Bilayer Graphene ◽  
The Impact

Graphene is a good candidate for protective material owing to its extremely high stiffness and high strength-to-weight ratio. However, the impact performance of twisted bilayer graphene is still obscure. Herein we have investigated the ballistic resistance capacity of twisted bilayer graphene compared to that of AA-stacked bilayer graphene using molecular dynamic simulations. The energy propagation processes are identical, while the ballistic resistance capacity of the twisted bilayer graphene is almost two times larger than the AA-bilayer graphene. The enhanced capacity of the twisted bilayer graphene is assumed to be caused by the mismatch between the two sheets of graphene, which results in earlier fracture of the first graphene layer and reduces the possibility of penetration.

On the Design and Analysis of Acoustic Horns for Ultrasonic Welding Teflon Encapsulated O-Ring

2013 ◽  
Vol 753-755 ◽  
pp. 402-406
Author(s):  
Kuen Ming Shu ◽  
Yu Jen Wang ◽  
Hoa Shen Yen
Keyword(s):  
Finite Element ◽  
Natural Frequencies ◽  
High Energy ◽  
Ultrasonic Welding ◽  
Ultrasonic Machining ◽  
Analysis And Design ◽  
Vital Part ◽  
Finite Element Software ◽  
Acoustic Horns

The acoustic horn plays a very vital part in high energy ultrasonic machining, and its design is critical to the quality and the efficiency of ultrasonic machining. This paper performs the analysis and design of acoustic horns for ultrasonic welding Teflon encapsulated O-ring by employing ANSYS finite element software. Firstly, the theoretical dimensions of the horns are calculated. Moreover, their natural frequencies and amplitudes are obtained through the simulations of ANSYS.

scholarly journals Collapse Analysis of a Transmission Tower-Line System Induced by Ice Shedding

2021 ◽  
Vol 9 ◽  
Author(s):  
Jiaxiang Li ◽  
Biao Wang ◽  
Jian Sun ◽  
Shuhong Wang ◽  
Xiaohong Zhang ◽  
...  
Keyword(s):  
Finite Element ◽  
Transmission Lines ◽  
Progressive Collapse ◽  
Element Model ◽  
Transmission Tower ◽  
Line System ◽  
Finite Element Software ◽  
Transmission Towers ◽  
Ice Shedding ◽  
The Impact

Ice shedding causes transmission lines to vibrate violently, which induces a sharp increase in the longitudinal unbalanced tension of the lines, even resulting in the progressive collapse of transmission towers in serious cases, which is a common ice-based disaster for transmission tower-line systems. Based on the actual engineering characteristics of a 500 kV transmission line taken as the research object, a finite element model of a two-tower, three-line system is established by commercial ANSYS finite element software. In the modeling process, the uniform mode method is used to introduce the initial defects, and the collapse caused by ice shedding and its influencing parameters are systematically studied. The results show that the higher the ice-shedding height is, the greater the threat of ice shedding to the system; furthermore, the greater the span is, the shorter the insulator length and the greater the dynamic response of the line; the impact of ice shedding should be considered in the design of transmission towers.

Finite Element Analysis of X-Cor Sandwich's Compressive Strength

2011 ◽  
Vol 306-307 ◽  
pp. 733-737
Author(s):  
Xu Dan Dang ◽  
Xin Li Wang ◽  
Hong Song Zhang ◽  
Jun Xiao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Compressive Strength ◽  
Failure Modes ◽  
Failure Mechanisms ◽  
Element Model ◽  
Failure Criteria ◽  
Stiffness Degradation ◽  
Element Analysis ◽  
Finite Element Software

In this article the finite element software was used to analyse the values for compressive strength of X-cor sandwich. During the analysis, the failure criteria and materials stiffness degradation rules of failure mechanisms were proposed. The failure processes and failure modes were also clarified. In the finite element model we used the distributions of failure elements to simulate the failure processes. Meanwhile the failure mechanisms of X-cor sandwich were explained. The finite element analysis indicates that the resin regions of Z-pin tips fail firstly and the Z-pins fail secondly. The dominant failure mode is the Z-pin elastic buckling and the propagation paths of failure elements are dispersive. Through contrast the finite element values and test results are consistent well and the error range is -7.6%~9.5%. Therefore the failure criteria and stiffness degradation rules are reasonable and the model can be used to predict the compressive strength of X-cor sandwich.

Techniques in Finite Element Modeling of Helmeted-Head Biomechanics

2009 ◽  
Author(s):  
Andrzej Przekwas ◽  
X. G. Tan ◽  
Z. J. Chen ◽  
Xianlian Zhou ◽  
Debbie Reeves ◽  
...  
Keyword(s):  
Finite Element ◽  
Brain Injury ◽  
Injury Risk ◽  
High Energy ◽  
Dense Layer ◽  
Hard Material ◽  
Absorption Mechanism ◽  
Military Applications ◽  
Main Components ◽  
The Impact

Generally a helmet comprises two main components: the shell and the fitting system. Despite the variations in designs due to the different usage requirements, typically helmets are intended to protect the user’s head through an energy absorption mechanism. The weight and volume are important factors in helmet design since both may alter the injury risk to the head and neck. The helmet outer shell is usually made of hard material that will deform when it is hit by hard objects. This action disperses energy from the impact to lessen the force before it reaches the head. The fitting system frequently includes a dense layer that cushions and absorbs the energy as a result of relative motion between the helmet and the head. A balance needs to be achieved on how strong and how stiff a helmet should be to provide the best possible protection. If a helmet is too stiff it can be less able to prevent brain injury in the kinds of impacts that may occur. If it is too flexible or soft, it might not protect the user in a violent, high-energy crash. For military applications, the requirements for helmet performance may be even more demanding. Not only do helmets have to protect a Soldier’s head from blunt impacts, but helmets also are expected to provide mounting platforms for ancillary devices and to function in ballistic and blast events as well.

Simulation of the Impact Behaviour of Diffusion-Bonded and Adhered Perforated Hollow Sphere Structures (PHSS)

2009 ◽  
Vol 294 ◽  
pp. 27-38 ◽  
Author(s):  
Fabian Ferrano ◽  
Marco Speich ◽  
Wolfgang Rimkus ◽  
Markus Merkel ◽  
Andreas Öchsner
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Finite Element ◽  
Mechanical Behaviour ◽  
Hollow Sphere ◽  
Large Deformations ◽  
The Finite Element Method ◽  
Impact Behaviour ◽  
New Type ◽  
The Impact

This paper investigates the mechanical properties of a new type of hollow sphere structure. For this new type, the sphere shell is perforated by several holes in order to open up the inner sphere volume and surface. The mechanical behaviour of perforated sphere structures under large deformations and strains in a primitive cubic arrangement is numerically evaluated by using the finite element method for different hole diameters and different joining techniques.

Research on the Numerical Simulation of Hot Stamping for High Strength Steel

2014 ◽  
Vol 898 ◽  
pp. 136-139
Author(s):  
Chang Feng Men ◽  
Wen Wen Du ◽  
Cui Hong Han
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
High Strength Steel ◽  
Hot Stamping ◽  
High Strength ◽  
Nonlinear Finite Element ◽  
Weight Percentage ◽  
Finite Element Software ◽  
Simulation Results ◽  
Die Temperature

In order to research on the hot stamping property of high strength steel, the stamping forming of USIBOR1500P is simulated by the nonlinear finite element software Dynaform and Ansys/ls-dyna. The initial data simulated on USIBOR1500P is obtained by the hot tensile test. The simulation results show that the martensite weight percentage and Vickers hardness are in inverse proportion to stamping speed and initial die temperature.

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