A Numerical Simulation on Ballistic Penetration Damage of 3D Orthogonal Woven Fabric at Microstructure Level

2011 ◽  
Vol 21 (2) ◽  
pp. 237-266 ◽  
Author(s):  
Xiwen Jia ◽  
Baozhong Sun ◽  
Bohong Gu
Keyword(s):  
Finite Element ◽  
Cross Sections ◽  
Impact Damage ◽  
Experimental Tests ◽  
Woven Fabric ◽  
Stress Wave Propagation ◽  
Rigid Projectile ◽  
Microstructure Model ◽  
3D Orthogonal Woven ◽  
The Impact

The ballistic impact damages of 3D orthogonal woven fabric (3DOWF) penetrated under a conically cylindrical rigid projectile were investigated from experimental tests and finite element simulations. A microstructure model of the 3DOWF was established and imported into finite element geometrical preprocessor. In the microstructure model, the architecture of the 3DOWF has the same spatial configurations with that of the real 3DOWF, including the spatial distributions and cross-sections of warp, weft yarns, and Z-yarns. Mechanical parameters of the yarns were obtained from high-strain rate tests which near to the impact loading condition in ballistic tests. The impact damage evolutions of the 3DOWF were simulated with the commercial finite element code ABAQUS/Explicit. From the comparisons of damage morphologies and residual velocities of the projectile after perforation between experimental and finite element simulation, it was found that the simulation can reflect the impact damage precisely. Furthermore, the stress wave propagation and damage mechanisms can be revealed from the microstructure model. Insights gained from this study will prove extremely useful in further material and architectural studies that will ultimately lead to optimization of the 3DOWF structure.

Ballistic penetration of conically cylindrical steel projectile into 3D orthogonal woven composite: a finite element study at microstructure level

2010 ◽  
Vol 45 (9) ◽  
pp. 965-987 ◽  
Author(s):  
Xiwen Jia ◽  
Baozhong Sun ◽  
Bohong Gu
Keyword(s):  
Finite Element ◽  
Impact Damage ◽  
Woven Composite ◽  
Strain Wave ◽  
Microstructure Model ◽  
Wave Distribution ◽  
Cylindrical Steel ◽  
3D Orthogonal Woven ◽  
The Impact ◽  
Ballistic Penetration

Ballistic penetration of conically cylindrical steel projectile into 3D orthogonal woven composite (3DOWC) was investigated from finite element analyses and ballistic impact tests. Based on the observation of the microstructure of the 3DOWC, a microstructure model was established for finite element calculation. In this model, the cross-section of warp, weft and Z-direction fiber tows was regarded as rectangular. The noninterwoven warp and weft yarns were bonded together with Z-yarns. The impact damage and energy absorption of the 3DOWC penetrated by a conically cylindrical steel projectile were calculated from the microstructure model and compared with the testing results. Good agreements with experiments have been observed, especially for deformation, damage evolution, and strain wave distribution in the 3DOWC under ballistic penetration.

Runway debris impact threat maps for transport aircraft

2014 ◽  
Vol 118 (1201) ◽  
pp. 229-266 ◽  
Author(s):  
S. N. Nguyen ◽  
E. S. Greenhalgh ◽  
J. M. R. Graham ◽  
A. Francis ◽  
R. Olsson
Keyword(s):  
Finite Element ◽  
Finite Element Modelling ◽  
Impact Damage ◽  
Landing Gear ◽  
Aerodynamic Forces ◽  
Element Modelling ◽  
Transport Aircraft ◽  
Lift And Drag ◽  
The Impact ◽  
Debris Impact

AbstractLarge transport aircraft are particularly susceptible to impact damage from runway debris thrown up by the landing gear. A methodology was developed to predict the trajectories of stones lofted by the nose wheel and subjected to aerodynamic forces due to the wake behind the nose landing gear and beneath the aircraft. In conjunction with finite element modelling of the stone/ground/tyre contact mechanics, an analytical model was used to perform a stochastic prediction of the trajectories of runway stones to generate impact threat maps which showed the relative likelihood of stones impinging upon various areas on the underside of a C-130 Hercules. The impact envelopes for the C-130 extended three to eighteen metres behind the nose wheel and two metres either side of the centre of the aircraft. The impact threat maps were especially sensitive to the values of the coefficients of lift and drag acting on the stone during its flight.

scholarly journals Damage detection in laminar thermoplastic composite materials by means of embedded optical fibers

2006 ◽  
Vol 60 (7-8) ◽  
pp. 176-179
Author(s):  
Aleksandar Kojovic ◽  
Irena Zivkovic ◽  
Ljiljana Brajovic ◽  
Dragan Mitrakovic ◽  
Radoslav Aleksic
Keyword(s):  
Composite Materials ◽  
Optical Fiber ◽  
Real Time ◽  
Optical Fibers ◽  
Impact Damage ◽  
Experimental Testing ◽  
Low Energy ◽  
Thermoplastic Composite ◽  
Woven Fabric ◽  
The Impact

This paper investigates the possibility of applying optical fibers as sensors for investigating low energy impact damage in laminar thermoplastic composite materials, in real time. Impact toughness testing by a Charpy impact pendulum with different loads was conducted in order to determine the method for comparative measurement of the resulting damage in the material. For that purpose intensity-based optical fibers were built in to specimens of composite materials with Kevlar 129 (the DuPont registered trade-mark for poly(p-phenylene terephthalamide)) woven fabric as reinforcement and thermoplastic PVB (poly(vinyl butyral)) as the matrix. In some specimens part of the layers of Kevlar was replaced with metal mesh (50% or 33% of the layers). Experimental testing was conducted in order to observe and analyze the response of the material under multiple low-energy impacts. Light from the light-emitting diode (LED) was launched to the embedded optical fiber and was propagated to the phototransistor-based photo detector. During each impact, the signal level, which is proportional to the light intensity in the optical fiber, drops and then slowly recovers. The obtained signals were analyzed to determine the appropriate method for real time damage monitoring. The major part of the damage occurs during impact. The damage reflects as a local, temporary release of strain in the optical fiber and an increase of the signal level. The obtained results show that intensity-based optical fibers could be used for measuring the damage in laminar thermoplastic composite materials. The acquired optical fiber signals depend on the type of material, but the same set of rules (relatively different, depending on the type of material) could be specified. Using real time measurement of the signal during impact and appropriate analysis enables quantitative evaluation of the impact damage in the material. Existing methods in most cases use just the intensity of the signal before and after the impact, as the measure of damage. This method could be used to monitor the damage in real time, giving warnings before fatal damage occurs.

Investigation of Stress Wave Propagation in Brain Tissues Through the Use of Finite Element Method

2010 ◽  
Author(s):  
Biaobiao Zhang ◽  
W. Steve Shepard ◽  
Candace L. Floyd
Keyword(s):  
Finite Element ◽  
Wave Propagation ◽  
Brain Injury ◽  
Stress Wave ◽  
Brain Research ◽  
Complex Structure ◽  
Stress Wave Propagation ◽  
Wave Loads ◽  
The Impact ◽  
The Brain

Because axons serve as the conduit for signal transmission within the brain, research related to axon damage during brain injury has received much attention in recent years. Although myelinated axons appear as a uniform white matter, the complex structure of axons has not been thoroughly considered in the study of fundamental structural injury mechanisms. Most axons are surrounded by an insulating sheath of myelin. Furthermore, hollow tube-like microtubules provide a form of structural support as well as a means for transport within the axon. In this work, the effects of microtubule and its surrounding protein mediums inside the axon structure are considered in order to obtain a better understanding of wave propagation within the axon in an attempt to make progress in this area of brain injury modeling. By examining axial wave propagation using a simplified finite element model to represent microtubule and its surrounding proteins assembly, the impact caused by stress wave loads within the brain axon structure can be better understood. Through conducting a transient analysis as the wave propagates, some important characteristics relative to brain tissue injuries are studied.

Experimentally validated predictive finite element modeling of the V0-V100 probabilistic penetration response of a Kevlar fabric against a spherical projectile

2018 ◽  
Vol 9 (4) ◽  
pp. 504-524 ◽  
Author(s):  
Gaurav Nilakantan
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Element Model ◽  
Ballistic Impact ◽  
Impact Testing ◽  
Woven Fabric ◽  
Projectile Impact ◽  
Element Modeling ◽  
The Impact

This work presents the first fully validated and predictive finite element modeling framework to generate the probabilistic penetration response of an aramid woven fabric subjected to ballistic impact. This response is defined by a V0-V100 curve that describes the probability of complete fabric penetration as a function of projectile impact velocity. The exemplar case considered in this article comprises a single-layer, fully clamped, plain-weave Kevlar fabric impacted at the center by a 0.22 cal spherical steel projectile. The fabric finite element model comprises individually modeled three-dimensional warp and fill yarns and is validated against the experimental material microstructure. Sources of statistical variability including yarn strength and modulus, inter-yarn friction, and precise projectile impact location are mapped into the finite element model. A series of impact simulations at varying projectile impact velocities is executed using LS-DYNA on the fabric models, each comprising unique mappings. The impact velocities and outcomes (penetration, non-penetration) are used to generate the numerical V0-V100 curve which is then validated against the experimental V0-V100 curve obtained from ballistic impact testing and shown to be in excellent agreement. The experimental data and its statistical analysis used for model input and validation, namely, the Kevlar yarn tensile strengths and moduli, inter-yarn friction, and fabric ballistic impact testing, are also reported.

Impact resistance of Nomex honeycomb sandwich structures with thin fibre reinforced polymer facesheets

2016 ◽  
Vol 20 (5) ◽  
pp. 531-552 ◽  
Author(s):  
Longquan Liu ◽  
Han Feng ◽  
Huaqing Tang ◽  
Zhongwei Guan
Keyword(s):  
Finite Element ◽  
Impact Energy ◽  
Sandwich Structures ◽  
Impact Resistance ◽  
Impact Response ◽  
Woven Fabric ◽  
Drop Weight ◽  
Honeycomb Sandwich ◽  
Nomex Honeycomb ◽  
The Impact

In order to investigate the impact resistance of the Nomex honeycomb sandwich structures skinned with thin fibre reinforced woven fabric composites, both drop-weight experimental work and meso-mechanical finite element modelling were conducted and the corresponding output was compared. Drop-weight impact tests with different impact parameters, including impact energy, impactor mass and facesheets, were carried out on Nomex honeycomb-cored sandwich structures. It was found that the impact resistance and the penetration depth of the Nomex honeycomb sandwich structures were significantly influenced by the impact energy. However, for impact energies that cause full perforation, the impact resistance is characterized with almost the same initial stiffness and peak force. The impactor mass has little influence on the impact response and the perforation force is primarily dependent on the thickness of the facesheet, which generally varies linearly with it. In the numerical simulation, a comprehensive finite element model was developed which considers all the constituent materials of the Nomex honeycomb, i.e. aramid paper, phenolic resin, and the micro-structure of the honeycomb wall. The model was validated against the corresponding experimental results and then further applied to study the effects of various impact angles on the response of the honeycomb. It was found that both the impact resistance and the perforation depth are significantly influenced by the impact angle. The former increases with the obliquity, while the latter decreases with it. The orientation of the Nomex core has little effect on the impact response, while the angle between the impact direction and the fibre direction of the facesheets has a great influence on the impact response.

Finite Element Analysis on the Blast Resistant Performance of Multibarrel Tube-Confined Concrete Column in Different Cross-Sections

2013 ◽  
Vol 721 ◽  
pp. 545-550
Author(s):  
Sai Wu ◽  
Jun Hai Zhao ◽  
Er Gang Xiong
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Detonation Wave ◽  
Cross Section ◽  
Cross Sections ◽  
Failure Modes ◽  
Circular Cross Section ◽  
Blast Load ◽  
Element Analysis ◽  
The Impact

Based on the finite element analysis software ANSYS/LS-DYNA, this paper numerically analyzed the dynamic performance of MTCCCs with different cross sections under blast load, followed by the study and comparison on the differences of the detonation wave propagation and failure modes between the columns in circular cross section and square cross section. The results show: The blast resistant performance of the circular component is more superior than the square component for its better aerodynamic shape that can greatly reduce the impact of the detonation wave on the column; The main difference of the failure modes between the circular and square cross-sectional components under blast load lies in the different failure mode of the outer steel tube. The simulation results in this paper can provide some references for the blast resisting design of MTCCCs.

scholarly journals Low-speed impact damage analysis of aviation composite material structure

2021 ◽  
Vol 260 ◽  
pp. 03021
Author(s):  
Jun He ◽  
Meng Cao ◽  
Zhishu Wang ◽  
Fanglin Cong
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Composite Material ◽  
Composite Structures ◽  
Impact Damage ◽  
Low Velocity Impact ◽  
Material Structure ◽  
Damage Analysis ◽  
Low Speed ◽  
The Impact

Although the carbon fiber reinforced composite material has high specific strength and stiffness, design-versatility, anti-corrosion and other excellent features, but the impact resistance of composite structures is poor. Therefore, the composite laminates low-speed damage analysis has important significance. Based on a three-dimensional analysis theory of cumulative damage, using the commercial finite element analysis software ABAQUS to establish laminates subjected to low velocity impact finite element model. according to the numerical results and the consistency of the test results, shows that the used model of the article is reasonable and accurate, and the numerical simulation method is verified to be feasible. Finally, through the numerical simulation of process of laminated plates low speed impact damage, the damage characteristics and damage mechanism of the laminates at different times are analyzed, and the forming reasons and expanding rules of the main damage forms of fiber damage and matrix damage are revealed.

Finite Element Stress Response Analysis of Stepped-Lap Adhesive Joints Subjected to Impact Tensile Load

2000 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Takahiro Ohmori
Keyword(s):  
Finite Element ◽  
Wave Propagation ◽  
Principal Stress ◽  
Impact Load ◽  
Maximum Principal Stress ◽  
Adhesive Joints ◽  
Stress Wave Propagation ◽  
Maximum Value ◽  
Adhesive Thickness ◽  
The Impact

Abstract The stress wave propagation and the stress distribution in stepped-lap adhesive joints of similar adherends subjected to impact tensile loads and elastic deformation are analyzed using three-dimensional finite-element method (FEM). The impact load is applied to the joint by dropping a weight. One end of the upper adherend is fixed, and the other end of the lower adherend is subjected to an impact load. FEM code employed is DYNA3D. The effects of Young’s modulus of the adherends, the number of lapped steps, and the adhesive thickness on the stress wave propagation at the lapped, and fee butted interfaces are examined. It is also found that the maximum value of the maximum principal stress σ1 occurs at the end of the butted interface between the adhesive and the lower adherend to which the impact load is applied. As the number of the lapped steps increases, the maximum value of the maximum principal stress σ1 increases. It is found that the maximum value of the maximum principal stress σ1 increases as the adhesive thickness decreases. The maximum value of σ1 increases as Young’s modulus of the adherends increases. In addition, the experiments were carried out to measure the strain response of stepped-lap adhesive joints subjected to impact tensile loads using strain gauges. A fairly good agreement is seen between the analytical, and the experimental results.

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