Projectile Impact Testing Aluminum Corrugated Core Composite Sandwiches Using Aluminum Corrugated Projectiles: Experimental and Numerical Investigation

2018 ◽  
Vol 910 ◽  
pp. 102-108
Author(s):  
Kutlay Odaci ◽  
Cenk Kılıçaslan ◽  
Alper Taşdemirci ◽  
Athanasios G. Mamalis ◽  
Mustafa Güden
Keyword(s):  
Impact Test ◽  
Composite Plates ◽  
Material Model ◽  
Impact Testing ◽  
Model Parameters ◽  
Projectile Impact ◽  
Composite Sandwich ◽  
Test Models ◽  
Polyester Composite ◽  
The Face

E-glass/polyester composite plates and 1050 H14 aluminum trapezoidal corrugated core composite sandwich plates were projectile impact tested using 1050 H14 aluminum trapezoidal fin corrugated projectiles with and without face sheets. The projectile impact tests were simulated in LS-DYNA. The MAT_162 material model parameters of the composite were determined and then optimized by the quasi-static and high strain rate tests. Non-centered projectile impact test models were validated by the experimental and numerical back face displacements of the impacted plates. Then, the centered projectile impact test models were developed and the resultant plate displacements were compared with those of the TNT mass equal Conwep simulations. The projectiles with face sheets induced similar displacement with the Conwep blast simulation, while the projectiles without face sheets underestimated the Conwep displacements, which was attributed to more uniform pressure distribution with the use of the face sheets on the test plates.

Phenomenological Modeling of Carpeted Surface for Drop Simulation of Portable Electronics

2019 ◽  
Vol 141 (2) ◽  
Author(s):  
Abhi Sirimamilla ◽  
Hua Ye ◽  
Yinan Wu
Keyword(s):  
Mechanical Response ◽  
Viscoelastic Model ◽  
Single Layer ◽  
Material Model ◽  
Impact Testing ◽  
Consumer Electronics ◽  
Model Parameters ◽  
Portable Devices ◽  
Impact Surface ◽  
The Impact

Using finite element (FE) analysis to simulate drop impact is widely adopted by the consumer electronics industry in the design process of portable devices. Most of such simulations model impact surface as a rigid or simple elastic surface. While this approach is valid for many common hard surfaces such as wood, tile, or concrete, it often does not provide a realistic risk assessment if the impact surface is a soft surface such as carpet. This paper describes a methodology to create a material model for carpeted impact surface that is suited for FE drop simulation. A multilayer hyperelastic–viscoelastic material model is used to model the mechanical response of the carpet under mechanical impact. Quasi-static and impact testing on the industrial carpet were performed to calibrate the model parameters with the help of optimization. Validation of the model was done by comparing the simulation predictions with measurements from the impact tests performed at different heights. Much better correlation between experimental measurements and simulation predictions were observed when using the multilayer hyper-viscoelastic model for carpet than using a single layer homogenous model. This approach can provide a better estimate and a more accurate representation for device drop risk on carpeted surfaces for design and development of portable products. The methodology can also be used to derive material models for other similar impact surfaces.

Verification of the Charpy Impact Test Capability to Determine the Constants of the Johnson-Cook Model

2016 ◽  
Vol 250 ◽  
pp. 197-202 ◽  
Author(s):  
Michal Stopel Stopel ◽  
Dariusz Skibicki
Keyword(s):  
Experimental Test ◽  
Impact Test ◽  
Charpy Impact ◽  
Material Model ◽  
Charpy Impact Test ◽  
Feasibility Analysis ◽  
Model Parameters ◽  
Strain Rates ◽  
Split Hopkinson

Feasibility analysis of replacing split Hopkinson bars test by Charpy impact test for determination of Johnson-Cook’s material model parameters. The results show that the Charpy impact test may, due to the strain rates achieved, successfully replace the mentioned experimental test. Moreover the results shows that some further studies should be conducted to improve efficiency of the proposed method.

scholarly journals Contribution to Reduce the Influence of the Free Sliding Edge on Compression-After-Impact Testing of Thin-Walled Undamaged Composites Plates

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1708 ◽  
Author(s):  
Markus Linke ◽  
Juan García-Manrique
Keyword(s):  
Impact Test ◽  
Composite Plates ◽  
Free Edge ◽  
Standard Test ◽  
Impact Testing ◽  
Reinforced Plastics ◽  
Compression After Impact ◽  
Fiber Reinforced Plastics ◽  
Thin Walled ◽  
Edge Influence

Standard Compression-After-Impact test devices show a weakening effect on thin-walled specimens due to a free panel edge that is required for compression. As a result, thin-walled undamaged samples do not break in the free measuring area but near the free edge and along the supports. They also show a strength reduction due to the free edge which can become potentially relevant for very weakly damaged panels. In order to reduce the free edge influence on the measured strength, a modified Compression-After-Impact test device has been developed. In an experimental investigation with carbon fiber reinforced plastics, the modified device is compared with a standard device. It is shown that thin-walled undamaged specimens investigated with the modified device now mainly break within the free measuring area and no longer at the free edge and along the bearings as it is the case for standard test devices. The modified device does not cause a free edge weakening effect in comparison to standard devices. The modified device is therefore more suitable for determining the compression strengths of undamaged thin-walled composite plates.

Impact response of composite plates manufactured with stitch-bonded non-crimp glass fiber fabrics

2014 ◽  
Vol 21 (1) ◽  
pp. 111-120 ◽  
Author(s):  
Numan Behlül Bektaş ◽  
İnan Ağır
Keyword(s):  
Glass Fiber ◽  
Matrix Material ◽  
Testing Machine ◽  
Composite Plates ◽  
Impact Testing ◽  
Impact Response ◽  
Damage Initiation ◽  
Polyester Composite ◽  
Impact Energies ◽  
The Impact

AbstractThis experimental study deals with the impact response of composite plates manufactured with stitch-bonded non-crimp glass fiber fabrics. Three kinds of fabrics – biaxial, triaxial, and quadraxial – are used as reinforcing material. Polyester resin is used as a matrix material in the composition of composite plates. An instrumented drop weight impact testing machine, Instron-Dynatup 9250 HV, is used for impact testing. Impact tests are performed under various impact energies, ranging from damage initiation to final perforation. An energy profiling method, showing the relation between impact energy and absorbed energy, was used together with load-deflection curves to determine the penetration and perforation thresholds of those composites. The failure processes of damaged specimens for different impact energies were evaluated by comparing load-deflection curves and images of damaged samples taken from the impacted and non-impacted sides. All types of composites have obvious penetration and perforation thresholds. The perforation threshold of triaxial/polyester composite is approximately 27% and 22% higher than that of the quadraxial and biaxial/polyester composites, respectively.

scholarly journals Variation of Passive Biomechanical Properties of the Small Intestine along Its Length: Microstructure-Based Characterization

2021 ◽  
Vol 8 (3) ◽  
pp. 32
Author(s):  
Dimitrios P. Sokolis
Keyword(s):  
Small Intestine ◽  
Orientation Angle ◽  
Axial Direction ◽  
Material Model ◽  
Biomechanical Properties ◽  
Intestinal Wall ◽  
Model Parameters ◽  
Material Models ◽  
Hyper Elastic ◽  
Rat Tissue

Multiaxial testing of the small intestinal wall is critical for understanding its biomechanical properties and defining material models, but limited data and material models are available. The aim of the present study was to develop a microstructure-based material model for the small intestine and test whether there was a significant variation in the passive biomechanical properties along the length of the organ. Rat tissue was cut into eight segments that underwent inflation/extension testing, and their nonlinearly hyper-elastic and anisotropic response was characterized by a fiber-reinforced model. Extensive parametric analysis showed a non-significant contribution to the model of the isotropic matrix and circumferential-fiber family, leading also to severe over-parameterization. Such issues were not apparent with the reduced neo-Hookean and (axial and diagonal)-fiber family model, that provided equally accurate fitting results. Absence from the model of either the axial or diagonal-fiber families led to ill representations of the force- and pressure-diameter data, respectively. The primary direction of anisotropy, designated by the estimated orientation angle of diagonal-fiber families, was about 35° to the axial direction, corroborating prior microscopic observations of submucosal collagen-fiber orientation. The estimated model parameters varied across and within the duodenum, jejunum, and ileum, corroborating histologically assessed segmental differences in layer thicknesses.

scholarly journals Flexural behavior of composite structural insulated panels with magnesium oxide board facings

2020 ◽  
Vol 20 (4) ◽  
Author(s):  
Łukasz Smakosz ◽  
Ireneusz Kreja ◽  
Zbigniew Pozorski
Keyword(s):  
Magnesium Oxide ◽  
Material Model ◽  
Expanded Polystyrene ◽  
Flexural Behavior ◽  
Joint Analysis ◽  
Model Parameters ◽  
Fe Model ◽  
Computational Results ◽  
Four Point Bending ◽  
Proposed Model

Abstract The current report is devoted to the flexural analysis of a composite structural insulated panel (CSIP) with magnesium oxide board facings and expanded polystyrene (EPS) core, that was recently introduced to the building industry. An advanced nonlinear FE model was created in the ABAQUS environment, able to simulate the CSIP’s flexural behavior in great detail. An original custom code procedure was developed, which allowed to include material bimodularity to significantly improve the accuracy of computational results and failure mode predictions. Material model parameters describing the nonlinear range were identified in a joint analysis of laboratory tests and their numerical simulations performed on CSIP beams of three different lengths subjected to three- and four-point bending. The model was validated by confronting computational results with experimental results for natural scale panels; a good correlation between the two results proved that the proposed model could effectively support the CSIP design process.

scholarly journals Considering multiple process observables to determine material model parameters for FE-cutting simulations

2021 ◽  
Author(s):  
Marvin Hardt ◽  
Thomas Bergs
Keyword(s):  
Chip Thickness ◽  
Material Model ◽  
Experimental Investigations ◽  
Model Parameters ◽  
Inverse Approach ◽  
Local Material ◽  
Novel Approach ◽  
Validation Parameters ◽  
Multiple Process ◽  
Cutting Simulations

AbstractAnalyzing the chip formation process by means of the finite element method (FEM) is an established procedure to understand the cutting process. For a realistic simulation, different input models are required, among which the material model is crucial. To determine the underlying material model parameters, inverse methods have found an increasing acceptance within the last decade. The calculated model parameters exhibit good validity within the domain of investigation, but suffer from their non-uniqueness. To overcome the drawback of the non-uniqueness, the literature suggests either to enlarge the domain of experimental investigations or to use more process observables as validation parameters. This paper presents a novel approach merging both suggestions: a fully automatized procedure in conjunction with the use of multiple process observables is utilized to investigate the non-uniqueness of material model parameters for the domain of cutting simulations. The underlying approach is two-fold: Firstly, the accuracy of the evaluated process observables from FE simulations is enhanced by establishing an automatized routine. Secondly, the number of process observables that are considered in the inverse approach is increased. For this purpose, the cutting force, cutting normal force, chip temperature, chip thickness, and chip radius are taken into account. It was shown that multiple parameter sets of the material model can result in almost identical simulation results in terms of the simulated process observables and the local material loads.

IMPACT ENERGY AND DUCTILITY INDEX OF KEVLAR REINFORCEMENT WITH KENAF POLYESTER COMPOSITE

2015 ◽  
Vol 76 (3) ◽  
Author(s):  
Noor Haznida Bakar ◽  
Koay Mei Hyie ◽  
C.M. Mardziah ◽  
N.R. Nik Roselina ◽  
Nik Rozlin Nik Masdek
Keyword(s):  
Impact Energy ◽  
Hybrid Composite ◽  
Impact Test ◽  
Impact Damage ◽  
Ductility Index ◽  
Absorption Energy ◽  
Polyester Composite ◽  
Naoh Solution ◽  
Impact Absorption Energy ◽  
Impact Absorption

This research focuses on the reinforcement of Kevlar in treated kenaf composite, specifically in the study of impact properties as well as the characteristics. The kenaf was treated with 6% Sodium Hydroxide (NaOH) solution at a specific period of time before being made into laminates. Impact test was conducted using an instrumented drop tower device at 36J level according to the standard ASTM D7136. Microstructures of the fractured specimens were also analyzed. The results of the study indicated that treated kenaf/Kevlar hybrid composite has better impact absorption energy than pure kenaf composite. Compared to the pure kenaf composite, the hybrid composite absorbs more impact energy and appears to have lower impact damage at the same impact energy level. This is because the Kevlar fibres play an important role to prevent and delay the destruction of composites.

scholarly journals Impact test of composite sandwich beam with built-in FBG sensor

2018 ◽  
Vol 397 ◽  
pp. 012028
Author(s):  
Haiping Pei ◽  
Yingying Wei ◽  
Yongzhen Chen ◽  
Li Wan ◽  
Weiqing Liu
Keyword(s):  
Impact Test ◽  
Sandwich Beam ◽  
Composite Sandwich ◽  
Fbg Sensor

Effect of Filler Compositions on the Mechanical Properties of Bamboo Filled Polyester Composite

2014 ◽  
Vol 879 ◽  
pp. 90-95 ◽  
Author(s):  
Abdul Rahman Noor Leha ◽  
Nor Amalina Nordin
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Impact Test ◽  
Compression Molding ◽  
Engineering Applications ◽  
Maximum Value ◽  
Polyester Composite ◽  
Bamboo Powder ◽  
Flexural Tests ◽  
The Impact

Biocomposite from bamboo powder was fabricated by compression molding technique. The objective of this study was to investigate the mechanical properties of bamboo compounded with epoxy with different ratio. Tensile and flexural tests were done to characterize its mechanical properties. It was observed that the strength of bamboo-polyester was increased with increasing amount of bamboo powder. The tensile and flexural strength shows the highest value at 25 wt.% bamboo. However, the impact test shows the maximum value at 20 wt.% bamboo powder. These results exhibit the bamboo-polyester can be a good candidate to be used in many engineering applications

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