scholarly journals An Experimental Study on the Impact Energy Absorption Mechanism of CFRP/Al Compound Square Tube

2015 ◽  
Vol 30 (6) ◽  
pp. 12-17
Author(s):  
Woo Chae Hwang ◽  
Cheon Seok Cha ◽  
Yong Jun Yang ◽  
Jong An Jung ◽  
In Young Yang
Keyword(s):  
Experimental Study ◽  
Energy Absorption ◽  
Impact Energy ◽  
Absorption Mechanism ◽  
The Impact

Numerical and Experimental Study on Railway Impact Energy Absorption Using Tube External Inversion Mechanism at Real Scale

2006 ◽  
Vol 306-308 ◽  
pp. 315-320 ◽  
Author(s):  
Ign Wiratmaja Puja ◽  
A. Khairullah ◽  
Muhammad Agus Kariem ◽  
A.H. Saputro
Keyword(s):  
Experimental Study ◽  
Numerical Analysis ◽  
Energy Absorption ◽  
Contact Force ◽  
Impact Energy ◽  
Experimental Result ◽  
Energy Absorber ◽  
The Impact ◽  
Inversion Mechanism ◽  
Real Scale

Impact energy and deceleration at a certain time are the most influenced factor to passenger’s safety when collision between railway vehicles occurred. In this paper, forced external inversion mechanism is considered as impact energy absorber. This mechanism is selected due to its constant inversion load along uniform tube [5] and the impact force is reduced because of its inertia effect [7]. Material used as energy absorber is mild steel. Numerical analysis using finite element method is utilized to study the energy absorption capacity and deceleration characteristic of tube external inversion mechanism for complex transient problem of collision. The real scale experimental study is used to validate the numerical analysis by crashing a moving vehicle to static train series where the impact energy absorber module using external inversion mechanism is attached in the tip of static train series. Characteristic that consider in numerical and experimental study are deformation and contact force. The deformation differences between numerical and experimental study are under 9%. Whereas for contact force, the experimental result of contact force disposed under 8% of numerical result for velocity of moving train at 10 and 15 km/h.

Effect of SiO2 Nanoparticles on the Mechanical and Low Velocity Impact Properties of Epoxy/Glass Composites

2016 ◽  
Vol 838 ◽  
pp. 29-35
Author(s):  
Michał Landowski ◽  
Krystyna Imielińska
Keyword(s):  
Flexural Strength ◽  
Energy Absorption ◽  
Impact Energy ◽  
Epoxy Matrix ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Nanoparticle Suspension ◽  
Impact Properties ◽  
Velocity Impact ◽  
The Impact

Flexural strength and low velocity impact properties were investigated in terms of possibile improvements due to epoxy matrix modification by SiO2 nanoparticles (1%, 2%, 3%, 5%, 7%wt.) in glass/epoxy laminates formed using hand lay-up method. The matrix resin was Hexion L285 (DGEBA) with Nanopox A410 - SiO2 (20 nm) nanoparticle suspension in the base epoxy resin (DGEBA) supplied by Evonic. Modification of epoxy matrix by variable concentrations of nanoSiO2 does not offer significant improvements in the flexural strength σg, Young’s modulus E and interlaminar shear strength for 1% 3% and 5% nanoSiO2 and for 7% a slight drop (up to ca. 15-20%) was found. Low energy (1J) impact resistance of nanocomposites represented by peak load in dynamic impact characteristics was not changed for nanocompoosites compared to the unmodified material. However at higher impact energy (3J) nanoparticles appear to slightly improve the impact energy absorption for 3% and 5%. The absence or minor improvements in the mechanical behaviour of nanocomposites is due to the failure mechanisms associated with hand layup fabrication technique: (i.e. rapid crack propagation across the extensive resin pockets and numerous pores and voids) which dominate the nanoparticle-dependent crack energy absorption mechanisms (microvoids formation and deformation).

Interplay of fabric structure and shear thickening fluid impregnation in moderating the impact response of high-performance woven fabrics

2020 ◽  
Vol 54 (28) ◽  
pp. 4387-4395
Author(s):  
Sanchi Arora ◽  
Abhijit Majumdar ◽  
Bhupendra Singh Butola
Keyword(s):  
Beneficial Effect ◽  
Energy Absorption ◽  
Impact Energy ◽  
High Performance ◽  
Research Work ◽  
Impact Resistance ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Fabric Structure ◽  
The Impact

The beneficial effect of STF impregnation in enhancing the impact resistance of high-performance fabrics has been extensively reported in the literature. However, this research work reports that fabric structure has a decisive role in moderating the effectiveness of STF impregnation in terms of impact energy absorption. Plain woven fabrics having sett varying from 25 × 25 inch−1 to 55 × 55 inch−1 were impregnated with STF at two different padding pressures to obtain different add-ons. The impact energy absorption by STF impregnated loosely woven fabrics was found to be higher than that of their neat counterparts for both levels of add-on, while opposite trend was observed in case of tightly woven fabrics. Further, comparison of tightly woven plain, 2/2 twill, 3/1 twill and 2 × 2 matt fabrics revealed beneficial effect of STF impregnation, except for the plain woven fabric, establishing that there exists a fabric structure-STF impregnation interplay that tunes the impact resistance of woven fabrics.

Dynamic Energy Absorption Performances of Rain Forest Vehicle (RFV) under Frontal Impact

2014 ◽  
Vol 67 (3) ◽  
Author(s):  
M. S. Othman ◽  
Z. Ahmad
Keyword(s):  
Energy Absorption ◽  
Impact Energy ◽  
Impact Loading ◽  
Rain Forest ◽  
Experimental Testing ◽  
Rigid Wall ◽  
Crash Analysis ◽  
Frontal Impact ◽  
Frontal Section ◽  
The Impact

This paper treats the crash analysis and energy absorption response of Rain Forest Vehicle (RFV) subjected to frontal impact scenario namely impacting rigid wall and column. Dynamic computer simulation techniques validated by experimental testing are used to carry out a crash analysis of such vehicle. The study aims at quantifying the energy absorption capability of frontal section of RFV under impact loading, for variations in the load transfer paths and geometry of the crashworthy components. It is evident that the proposed design of the RFV frontal section are desirable as primary impact energy mitigation due to its ability to withstand and absorb impact loads effectively. Furthermore, it is found that the impact energy transmitted to the survival room may feasibly be minimized in these two impact events. The primary outcome of this study is design recommendation for enhancing the level of safety of the off-road vehicle where impact loading is expected.   

Dynamic Energy Absorption Performances of Rain Forest Vehicle (RFV) under Frontal Impact

2014 ◽  
Vol 69 (3) ◽  
Author(s):  
M. S. Othman ◽  
Z. Ahmad
Keyword(s):  
Energy Absorption ◽  
Impact Energy ◽  
Impact Loading ◽  
Rain Forest ◽  
Experimental Testing ◽  
Rigid Wall ◽  
Crash Analysis ◽  
Frontal Impact ◽  
Frontal Section ◽  
The Impact

This paper treats the crash analysis and energy absorption response of Rain Forest Vehicle (RFV) subjected to frontal impact scenario namely impacting rigid wall and column. Dynamic computer simulation techniques validated by experimental testing are used to carry out a crash analysis of such vehicle. The study aims at quantifying the energy absorption capability of frontal section of RFV under impact loading, for variations in the load transfer paths and geometry of the crashworthy components. It is evident that the proposed design of the RFV frontal section are desirable as primary impact energy mitigation due to its ability to withstand and absorb impact loads effectively. Furthermore, it is found that the impact energy transmitted to the survival room may feasibly be minimized in these two impact events. The primary outcome of this study is design recommendation for enhancing the level of safety of the off-road vehicle where impact loading is expected.   

Low-velocity impact response of wood-strand sandwich panels and their components

Holzforschung ◽  
2018 ◽  
Vol 72 (8) ◽  
pp. 681-689 ◽  
Author(s):  
Mostafa Mohammadabadi ◽  
Vikram Yadama ◽  
LiHong Yao ◽  
Debes Bhattacharyya
Keyword(s):  
Energy Absorption ◽  
Impact Energy ◽  
Failure Modes ◽  
Sandwich Panels ◽  
Low Velocity Impact ◽  
Insulation Material ◽  
Low Velocity ◽  
Velocity Impact ◽  
Section Modulus ◽  
The Impact

AbstractProfiled hollow core sandwich panels (SPs) and their components (outer layers and core) were manufactured with ponderosa and lodgepole pine wood strands to determine the effects of low-velocity impact forces and to observe their energy absorption (EA) capacities and failure modes. An instrumented drop weight impact system was applied and the tests were performed by releasing the impact head from 500 mm for all the specimens while the impactors (IMPs) were equipped with hemispherical and flat head cylindrical heads. SPs with cavities filled with a rigid foam insulation material (SPfoam) were also tested to understand the change in EA behavior and failure mode. Failure modes induced by both IMPs to SPs were found to be splitting, perforating, penetrating, core crushing and debonding between the core and the outer layers. SPfoams absorbed 26% more energy than unfilled SPs. SPfoams with urethane foam suffer less severe failure modes than SPs. SPs in a ridge-loading configuration absorbed more impact energy than those in a valley-loading configuration, especially when impacted by a hemispherical IMP. Based on the results, it is evident that sandwich structure is more efficient than a solid panel concerning impact energy absorption, primarily due to a larger elastic section modulus of the core’s corrugated geometry.

Energy Absorption Mechanisms and Crash Analysis of Helicopter Seats

2018 ◽  
Author(s):  
Gülce Özturk ◽  
Altan Kayran
Keyword(s):  
Plastic Deformation ◽  
Energy Absorption ◽  
Strain Curve ◽  
Rigid Wall ◽  
Absorption Mechanism ◽  
Dynamic Simulations ◽  
Explicit Finite Element ◽  
Energy Absorbing ◽  
The Impact ◽  
Aluminum Material

In this paper, a crushable absorber system is designed to analyze the dynamic behavior and performance of a helicopter seat. The mechanism of the absorption system makes use of the crash energy to plastically deform the aluminum material of the seat legs. Seat structure is composed of a bucket, two legs and two sliding parts on each leg. Seat legs are made of aluminum and and the sliding parts of the seat are steel. During the impact event, the heavier sliding parts move down and crash the aluminum material for the purpose of deforming the aluminum material under the sliding parts and reduce the crash energy. The designed helicopter seat is analyzed using the explicit finite element method to evaluate how the seat energy absorbing mechanism works. Dynamic simulations are performed in ABAQUS by crashing the seat to a fixed rigid wall. To simulate the plastic deformation, true stress-strain curve of the aluminum material of the seat leg has been used. Time response results are filtered to calculate the meaningful g loads which incur damage to the occupants. Analyses are performed with and without the energy absorption mechanism in order to see the effectiveness of the energy absorption mechanism on the human survivability by comparing the g loads on the seat bucket with the acceptable loads specified by EASA. This study is a preliminary study intended to check the effectiveness of the damping mechanism based on the plastic deformation of the aluminum legs of the seat in the event of a crash.

Numerical Investigation on Impact Energy Absorption of Single-Walled Carbon Nanotube Reinforced Composites

2012 ◽  
Author(s):  
Lingyu Sun ◽  
Jian Zhang ◽  
Dingxin Leng
Keyword(s):  
Numerical Investigation ◽  
Energy Absorption ◽  
Impact Energy ◽  
Metal Matrix ◽  
Failure Modes ◽  
Volume Fraction ◽  
Matrix Material ◽  
Reinforced Composites ◽  
Alloy Matrix ◽  
The Impact

With the exceptional mechanical properties, carbon nanotubes (CNTs) are considered to be attractive candidate reinforcements for composite materials and to have potential applications in improving the energy absorption capability of matrix material. However, it is still difficult to reveal the micro-mechanisms of the impact energy absorption of CNT-reinforced composites by experiments, hence, the numerical investigation is helpful. In this paper, a unit cell of single-walled CNTs (SWCNTs) embedded in metal matrix is modeled by nano-scale finite element method. Under impact loads, the failure modes of a single SWCNT and the SWCNT in matrix are predicted, respectively, and several possible energy absorption mechanisms are explained and compared. The investigation shows that, the metal matrix restraints the radial expansion of the SWCNT and therefore improves its crush buckling resistance, and makes it absorb more energy before collapse. The specific energy absorption of SWCNTs-reinforce composites increases with the increasing volume fraction of SWCNTs in both matrixes, and ascends more quickly in magnesium alloy than in aluminum alloy matrix.

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