Numerical Evaluation of Stiffness and Energy Absorption of a Hybrid Unidirectional/Random Glass Fiber Composite

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Wensong Yang ◽  
Assimina A. Pelegri
Keyword(s):  
Finite Element ◽  
Glass Fiber ◽  
Energy Absorption ◽  
Specific Energy ◽  
Hybrid Composite ◽  
Fiber Composite ◽  
Element Model ◽  
Specific Energy Absorption ◽  
Cross Section Area ◽  
Glass Fiber Composite

A finite element method is employed to numerically evaluate the stiffness and energy absorption properties of an architecturally hybrid composite material consisting of unidirectional and random glass fiber layers. An ls-dyna finite element model of a composite hollow square tube is developed in which the position of the random fiber layers varies through the thickness. The assessment of the stiffness and energy absorption is performed via three-point impact and longitudinal crash tests at two speeds, 15.6 m/s (35 mph) and 29.0 m/s (65 mph), and five strain rates, ɛ· = 0.1 s−1, 1 s−1, 10 s−1, 20 s−1, and 40 s−1. It is suggested that strategic positioning of the random fiber microstructural architecture into the hybrid composite increases its specific absorption energy and, therefore, enhances its crashworthiness. The simulation data indicate that the composite structure with outer layers of unidirectional lamina followed by random fiber layers is the stiffest due to the considerable superior specific energy absorption of the random fiber micro-architecture. Moreover, it is illustrated that the specific energy absorption increases with the increased ratio of impact contact area over cross-section area. Of all the parameters tested the thickness of the unidirectional laminate on the specific energy absorption does not appear to have a significant effect at the studied thickness ratios.

Efficient crushable corrugated conical tubes for energy absorption considering axial and oblique loading

2018 ◽  
Vol 233 (11) ◽  
pp. 3917-3935 ◽  
Author(s):  
Alireza Ahmadi ◽  
Masoud Asgari
Keyword(s):  
Finite Element ◽  
Energy Absorption ◽  
Specific Energy ◽  
Axial Loading ◽  
Element Model ◽  
Compression Tests ◽  
Static Compression ◽  
Specific Energy Absorption ◽  
Thin Walled Structures ◽  
Absorption Characteristics

Thin-walled structures are of much interest as energy absorption devices for their great crashworthiness and also low weight. Conical tubes are favorable structures because unlike most other geometries, they are also useful in oblique impacts. This paper investigated the effect of corrugations on energy absorption characteristics of conical tubes under quasi-static axial and oblique loadings. To do so, conical tubes with different corrugation geometries were analyzed using the finite element explicit code and the effects of corrugations on initial peak crushing force and specific energy absorption were studied. The finite element model was validated by experimental quasi-static compression tests on simple and corrugated aluminum cylinders. An efficient analytical solution for EA during axial loading was also derived and compared with the FEM solution. The crushing stableness was analyzed using the undulation of the load-carrying capacity parameter and it was shown that corrugations made collapsing mode, more predictable and controllable. The findings have shown that corrugated conical tubes have much better energy absorption characteristics compared with their non-corrugated counterparts. It was also discovered that during oblique loadings, introducing corrugations can significantly increase the specific energy absorption compared with simple cones.

scholarly journals Influence of Polymer Composites and Memory Foam on Energy Absorption in Vehicle Application

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1222 ◽  
Author(s):  
Ana Pilipović ◽  
Petar Ilinčić ◽  
Jelena Petruša ◽  
Zoran Domitran
Keyword(s):  
Glass Fiber ◽  
Polymer Composites ◽  
Energy Absorption ◽  
Carbon Fibers ◽  
Hybrid Composite ◽  
Influence Factor ◽  
Impact Force ◽  
Fiber Composite ◽  
Glass Fiber Composite ◽  
The Impact

The automotive industry is one of the biggest consumers of polymer composites. Aside from good mechanical properties, polymer composites have low mass, which positively affects the overall vehicle weight reduction and improves energy efficiency. Although polymer composites are used in various vehicle components, this paper focused on the application in vehicle bumper production. Two different composite plates with hybrid fiber layup were made; the first plate with a combination of glass and carbon fibers and the second with carbon and aramid. For comparison, and as a cheaper variant, a third plate was made only with glass fibers. In the first two plates, epoxy resin was used as the matrix, while in the third plate, polyester resin was used. Polyurethane memory foams of different densities (60, 80, 100 kg/m3) and thicknesses (10, 15, 20 mm) were used as impact force energy absorbers. With the factorial design of experiments, it was found that the thickness of the memory foam was the main influence factor. Without the use of memory foam, the hybrid composite, made of glass and carbon fibers, showed the highest energy absorption, while with the use of foam, the highest energy absorption was achieved with the glass fiber composite. Without the memory foam, the impact force measured on the glass/carbon hybrid composite was 9319.11 ± 93.18 N. Minimum impact force to the amount of 5143.19 ± 237.65 N was measured when the glass fiber composite plate was combined with the memory foam. When using memory foam, the impact force was reduced by 30–48%, depending on the type of composite used.

Energy Absorption of Braided Glass Fiber Reinforced Composite Tubes

2000 ◽  
Author(s):  
Shu Ching Quek ◽  
Anthony M. Waas
Keyword(s):  
Glass Fiber ◽  
Energy Absorption ◽  
Damage Mechanics ◽  
Progressive Failure ◽  
Fiber Composite ◽  
Continuum Damage Mechanics ◽  
Composite Tubes ◽  
Reinforced Composite ◽  
Glass Fiber Reinforced ◽  
Glass Fiber Composite

Abstract Results from an experimental and analytical study on the behavior of braided glass fiber composite tubes under quasi-static crush conditions are presented. The composite tubes have an initiator plug introduced at one open end (chamfered) while the other end is clamped. This procedure causes the tube to ‘flare’ outwards into fronds and results in the progressive failure of the tube in the axial and hoop direction without global tube buckling. Axial force and axial displacements are measured during these tests in order to assess energy absorption. In addition, readings from strain gages that are placed at critical locations on the tube walls are used to assess the state of strain on the tube walls away from the crush end. During a crush test, the axial load ascended to a maximum value and subsequently settled to a plateau value about which the load oscillated during the progressive crushing of the tube. The oscillations exhibited distinct periodicity. Results from an analytical model that best simulates the failure of these tubes are presented. The model is based on an axisymmetric formulation of the cylindrical shell equations in conjunction with ideas from classical fracture mechanics and continuum damage mechanics.

Ballistic Performance Evaluation of Kevlar-Glass Fibre Hybrid Composite Laminate against Medium Velocity Impact

2021 ◽  
Vol 1165 ◽  
pp. 47-64
Author(s):  
Saurabh S. Kumar ◽  
Rajesh G. Babu ◽  
U. Magarajan
Keyword(s):  
Energy Absorption ◽  
Specific Energy ◽  
Glass Fibre ◽  
Hybrid Composite ◽  
Composite Laminates ◽  
Areal Density ◽  
Ballistic Performance ◽  
Performance Requirement ◽  
Specific Energy Absorption ◽  
Fabric Composite

In this paper, the post ballistic impact behaviour of kevlar-glass fibre hybrid composite laminates was investigated against 9×19 mm projectile. Eight different types of composite laminates with different ratios of kevlar woven fibre to glass fibre were fabricated using hand lay-up with epoxy matrix. Ballistic behaviour like ballistic Limit (V50), energy absorption, specific energy absorption and Back Face Signature (BFS) were studied after bullet impact. The results indicated that as the Percentage of glass fibre is increased there was a linear increment in the ballistic behaviour. Addition of 16% kevlar fabric, composite sample meets the performance requirement of NIJ0101.06 Level III-A. Since the maximum specific energy absorption was observed in Pure Kevlar samples and the adding of glass fibre increases the weight and Areal Density of the sample, further investigations need to be carried out to utilize the potential of glass fibre for ballistic applications.

Crashworthiness performance of concentric structures with different cross-sectional shapes under multiple loading conditions

2020 ◽  
pp. 095440702096188
Author(s):  
Sadjad Pirmohammad
Keyword(s):  
Energy Absorption ◽  
Specific Energy ◽  
Absorption Maximum ◽  
Element Model ◽  
Hexagonal Structure ◽  
Loading Conditions ◽  
Cross Sectional ◽  
Specific Energy Absorption ◽  
Multiple Loading ◽  
Energy Absorbing

This paper evaluates the crashworthiness performance of concentric structures with different numbers of tubes (i.e. one to five) and cross-sectional shapes (i.e. hexagon, octagon, decagon and circle) under the multiple loadings of θ = 0, 10, 20 and 30°. An experimentally validated finite element model generated in LS-DYNA is employed to calculate the crashworthiness parameters including the specific energy absorption, maximum crush force and crush force efficiency. A total of 20 concentric structures are analyzed to explore the effects of number of tubes and cross-sectional shapes on the crushing performance. A multi-criteria decision-making method known as TOPSIS is also used to compare and rank the concentric structures in terms of crushing performance. Based on the results, the hexagonal structure including two tubes and octagonal, decagonal and circular structures including three tubes demonstrate the best results among their corresponding cross-sectional shapes. These structures show 9, 39, 38 and 39% higher specific energy absorption compared to their corresponding single tubal cases, respectively. However, in comparison to single tubal cases, they generate 4, 57, 57 and 58% higher maximum crush force, respectively. As such, the values for the improvement of the crush force efficiency are 3, 26, 25 and 21%, respectively. Furthermore, the decagonal structure including three tubes provides the highest energy absorbing characteristics as compared with all the other structures studied in this research. Meanwhile, taking into account all the multiple loading conditions, this structure shows 50% higher specific energy absorption than the hexagonal structure including single tube (as the weakest structure).

Impact Energy Absorption of Continuous Fiber Composite Tubes

1987 ◽  
Vol 109 (1) ◽  
pp. 72-77 ◽  
Author(s):  
D. W. Schmueser ◽  
L. E. Wickliffe
Keyword(s):  
Energy Absorption ◽  
Specific Energy ◽  
Failure Modes ◽  
Fiber Composite ◽  
Impact Testing ◽  
Compression Tests ◽  
Buckling Mode ◽  
Static Compression ◽  
Specific Energy Absorption ◽  
Fiber Splitting

This paper presents the results of an impact testing program that was conducted to characterize the energy absorption and failure characteristics of selected composite material systems and to compare the results with aluminum and steel. Composite tube specimens were constructed using graphite/epoxy (Gr/Ep), Kevlar/epoxy (K/Ep), and glass/epoxy (Gl/Ep) prepreg tape and were autoclave cured. Vertical impact and static compression tests were performed on 56 tubes. Tests results for energy absorption varied significantly as a function of lay-up angle and material type. In general, the Gr/Ep tubes had specific energy absorption values that were greater than those for K/Ep and Gl/Ep tubes having the same ply construction. Angle-ply Gr/Ep and K/Ep tubes had specific energy absorption values that were greater than those for 1024 steel tubes. Gr/Ep and Gl/Ep angle-ply tubes exhibited brittle failure modes consisting of fiber splitting and ply delamination, whereas the K/Ep angle-ply tubes collapsed in an accordian buckling mode similar to that obtained for metal tubes.

Flexural and Impact Properties of 2D and 3D Jute/GF/Epoxy Hybrid Composite Materials

2015 ◽  
Vol 766-767 ◽  
pp. 178-182
Author(s):  
N.R.R. Anbusagar ◽  
K. Palanikumar ◽  
R. Mohanarangan ◽  
P. Sengottuvel
Keyword(s):  
Flexural Strength ◽  
Glass Fiber ◽  
Hybrid Composite ◽  
Hybrid Composites ◽  
Fiber Composite ◽  
Three Dimensional ◽  
Glass Fiber Composite ◽  
Nylon Fiber ◽  
2D And 3D ◽  
The Impact

In order characterize the outstanding performance of the three dimensional (3D) hybrid composites, the charpy and flexural test has been carried out. 3D fiber structures have been achieved by using hand lay-up process and machine stitching method. Materials for hand lay-up and machine stitching process were glass fiber, jute fiber, and epoxy resin and nylon fiber respectively. Two dimensional (2D) glass fiber composite and 2D hybrid composite with the same stacking sequence as three dimensional (3D) counterparts have also been fabricated for the comparison of impact and flexural strength. The impact strength of 3D hybrid composite was increased (5-10%) compared with that 2D glass fiber and 2D hybrid composites. The flexural strength and modulus of 3D hybrid composite were increased (5-10%) compared with that of 2D hybrid composites.

Energy absorption characteristics of thin-walled steel tube filled with paper scraps

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5985-6002
Author(s):  
Peng Cheng ◽  
Qingchun Wang ◽  
Shi Ke
Keyword(s):  
Finite Element ◽  
Energy Absorption ◽  
Specific Energy ◽  
Steel Tube ◽  
Specific Energy Absorption ◽  
Crushing Force ◽  
Thin Walled Tube ◽  
The Mean ◽  
Thin Walled ◽  
Absorption Characteristics

The specific energy absorption of a thin-walled tube can be improved by filler. This study examined the potential use of a cheaper biomass filler, paper scraps, to enhance the energy absorption characteristics of the structure while reducing its cost, compared to that with a traditional filler such as foam material. Quasi-static crushing tests and finite element simulations were performed by using the explicit non-linear finite element software LS-DYNA to determine the improvements to the mean crushing force and specific energy absorption of the steel tube when filled with different densities of paper scraps. The mean crushing force and specific energy absorption of the empty tube, the paper scraps, and thin-walled tube filled with paper scraps were determined, and corresponding numerical simulations were performed. The simulation and test results showed that the impact performance of tube filled with paper scraps was greatly improved when paper scraps density was 0.35 g/cm3. By optimizing paper scraps filling structure, a new structure that could further enhance the specific energy absorption was obtained. The optimal scheme could increase the specific energy absorption of Q345 steel tube by 11.35%.

Evaluation of Damping for Glass Fiber Reinforced Composite Materials

2012 ◽  
Vol 488-489 ◽  
pp. 654-658
Author(s):  
Pramod Kumar
Keyword(s):  
Glass Fiber ◽  
Dynamic Characteristics ◽  
Mechanical Performance ◽  
Fiber Composite ◽  
Element Model ◽  
Experimental Result ◽  
Material System ◽  
Reinforced Composite ◽  
Glass Fiber Reinforced ◽  
Glass Fiber Composite

A structural composite is a material system consisting of two or more phases on macroscopic scale whose mechanical performance and properties are designed to be superior to those of the constituent materials acting independently. One of the phases is stiffer and stronger and is called reinforcement and less stiff and weaker phase is known as matrix. This paper presents an experimental analysis of the dynamic characteristics of the unidirectional fiber composite as functions of fiber orientation, temperature, frequency and ramp rate. Dynamic characteristics of glass fiber composite are measured using dynamic machine analyzer (Triton 2000) in three point flexure bending. Micromechanical finite element model is modeled in NISA FEM software and damping of composite material is predicted and results are compared with experimental result.

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