TWO-WAY ENERGY-ABSORBING CAB SUPPORT OF LOGGING MACHINE

Author(s):  
Скобцов ◽  
I. Skobtsov

This article deals with the way of increasing energy absorption capacity of forest machine cabin Roll-Over Protective Structure, that’s provides operator’s protection during an accidental rollover

2013 ◽  
Vol 437 ◽  
pp. 158-163
Author(s):  
Wei Liang Dai ◽  
Xu Guang Li ◽  
Qing Chun Wang

Energy absorbing characteristics of the non-stiffened and stiffened single hat sections subjected to quasi-static axial crushing were experimentally investigated. First non-stiffened hat sections were axially crushed, then structures with different stiffened methods (stiffened in hat and stiffened in the plate) were tested, finally energy absorption capacities of these structures were compared. Test results showed that, for the appropriate designed stiffened tube, the mean crush force and mass specific energy absorption were increased significantly compared to the non-stiffened. Stiffened in hat section showed a little more energy absorption capacity than that stiffened in the plate, but the structure may sustain a global bending.


Author(s):  
Muhammad Ali ◽  
Eboreime Ohioma ◽  
Khairul Alam

Square tubes are primarily used in automotive structures to absorb energy in the event of an accident. The energy absorption capacity of these structural members depends on several parameters such as tube material, wall thickness, axial length, deformation modes, locking strain, crushing stress, etc. In this paper, the work presented is a continuation of research conducted on exploring the effects of the introduction of cellular core in tubular structures under axial compressive loading. Here, the crushing response of composite cellular core tube was numerically studied using ABAQUS/Explicit module. The energy absorbing characteristics such as deformation or collapsing modes, crushing/ reactive force, crushing stroke, and energy curves were discussed. The composite cellular core tube shows promise for improving the crashworthiness of automobiles.


Author(s):  
J. M. Kelly ◽  
R. I. Skinner ◽  
A. J. Heine

A structure designed to resist earthquake attack must have a capacity to dissipate kinetic energy induced by the ground motion. In most structures this energy absorption is developed in the vicinity of beam to column connections. Recent research has shown that connections are not reliable when subject to cyclic loading, such as results from earthquake attack. Connections in steel frames deteriorate due to local instabilities in adjacent flanges, and in reinforced concrete frames alternating shear
loads produce diagonal tension and bond failures which progressively reduce the strength of the connection. Much work in building research and earthquake engineering in laboratories throughout the world is directed toward increasing the reliability and energy absorption capacity of structural connections. In this paper an alternative approach to this problem is described. This approach is to separate the load carrying function of the structure from the energy absorbing function and to ask if special devices could be incorporated into the structure with the sole purpose of absorbing the kinetic energy generated in the structure by earthquake attack. To determine whether such devices are feasible a study has been undertaken of three essentially different mechanisms of energy absorption. These mechanisms all utilized the plastic deformation of mild steel. They included the rolling of strips, torsion of square and rectangular bars,
 and the flexure of short thick beams. These mechanisms were selected for intensive study since they were basic to three different types of device each of which was designed for a separate mode of operation in a structural system. The characteristics of these mechanisms which were of primary importance in this study were the load displacement relations, the energy absorption capacity and the fatigue resistance. This information was obtained with a view to the development of devices for specific structural applications. This report describes the tests used to explore the basic mechanisms and the data obtained. It also include s a brief description of tests on scale models of a device which was designed to be located in the piers of a reinforced concrete railway bridge. It has been shown by the tests that the plastic torsion of mild steel is an extremely efficient mechanism for the absorption of energy. It was found that at plastic strains in the range 3% to 12% it was possible to develop energy dissipation of the order of 2000-7500 lb in/in3 per cycle (14-50 x 106 N/M2 per cycle) with lifetimes within the range of 1000 to 100 cycles. It was also shown that the mode of failure in torsion is an extremely favourable one for use in an energy absorbing device in that it took the form of a gradual decay. The other two mechanisms studied were both less efficient and less reliable than torsion and had capacities of 500-2000 lb in/in3 per cycle (3.5 - 14 x 106 N/M2 per cycle) and life times of around 200 to 20 cycles. Nevertheless they lend themselves to more compact devices than does the torsional mechanism and furthermore the devices may be located in regions in a structure where they are readily accessible for replacement after attack.


The aim of this study is to examine the effect of fiber mat’s density and deformation mechanism of tubes with and without die compression. In this study a new mode of deformation mechanism of density graded GFRP circular tube is examined when they are subjected to axial compression on to a die and without die to examine its energy absorbing capacity. Theoretical calculations were made to predict the crushing stress of different specimens. It is observed that increasing density of fiber increases energy absorption value but decreases the specific energy absorption and the die could trigger progressive crushing additionally decreasing peak load. Here the compressed tube wall is compelled to be deformed towards the end of compression die with a little range of bending curvature which was forced by the radius of the die at high crushing stress and the major part of the deformation takes place at a nearly constant load, which leads to high energy absorption capacity. Comparison between theoretical prediction values by derived equations and the experimental results shows good correlation.


2021 ◽  
Author(s):  
Ali Rashidian ◽  
Khandaker M. Anwar

This research studied the shear and flexural behaviour of fiber reinforced lightweight self-consolidating concrete (FRLWSCC) beams made of three different fibers such as: High-Density Poly Ethylene (HDPE), Crumb Rubber (CR) and Polyvinyl Alcohol (PVA) compared with lightweight self-consolidating concrete (LWSCC) beams. The performances of all beams were described based on load-deformation or moment-rotation response, strain developments, crack characterization, failure modes, ductility, stiffness and energy absorbing capacity. All FRLWSCC shear beams showed higher ultimate shear resistance, ductility and energy absorption capacity compared to LWSCC beams. All FRLWSCC flexural beams at failure exhibited higher flexural capacity, more cracks with smaller width, higher ductility, higher energy absorption capacity and lower stiffness compared to their LWSCC counterparts. FRLWSCC beams especially made of HDPE fibers showed better shear and flexural capacities besides satisfactory ductility performance. Experimental shear and flexural capacities of FRLWSCC beams were compared with those predicted from Code based and other existing equations.


2011 ◽  
Vol 462-463 ◽  
pp. 13-17 ◽  
Author(s):  
Yan Wang ◽  
P. Xue ◽  
J.P. Wang

Honeycomb materials,as a type of ultra-light multifunctional material,have been examined extensively in recent years and have been applied in many fields. This study investigated the energy absorption capacity and their mechanisms of honeycomb structures with five different cell geometry (square,triangular,circular, hexagonal,kagome). It has been shown that the honeycomb structure with kagome cells is the best choice under the targets of the energy absorption capacity, peak force and plateau stress, when relative density and cell wall thickness of the five kinds of honeycombs are the same. Besides, honeycomb with hexagonal cells and honeycomb with triangular cells are also ideal structures for energy absorption purpose.


2021 ◽  
Author(s):  
Ali Rashidian ◽  
Khandaker M. Anwar

This research studied the shear and flexural behaviour of fiber reinforced lightweight self-consolidating concrete (FRLWSCC) beams made of three different fibers such as: High-Density Poly Ethylene (HDPE), Crumb Rubber (CR) and Polyvinyl Alcohol (PVA) compared with lightweight self-consolidating concrete (LWSCC) beams. The performances of all beams were described based on load-deformation or moment-rotation response, strain developments, crack characterization, failure modes, ductility, stiffness and energy absorbing capacity. All FRLWSCC shear beams showed higher ultimate shear resistance, ductility and energy absorption capacity compared to LWSCC beams. All FRLWSCC flexural beams at failure exhibited higher flexural capacity, more cracks with smaller width, higher ductility, higher energy absorption capacity and lower stiffness compared to their LWSCC counterparts. FRLWSCC beams especially made of HDPE fibers showed better shear and flexural capacities besides satisfactory ductility performance. Experimental shear and flexural capacities of FRLWSCC beams were compared with those predicted from Code based and other existing equations.


Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4857
Author(s):  
Michal Rogala ◽  
Jakub Gajewski ◽  
Miroslaw Ferdynus

Crashworthiness of conical shells is known to depend on various factors. This study sets out to determine the extent to which the cross-sectional diameter contributes to their energy-absorbing properties. The object of the study was thin-walled aluminium tubes varying in upper diameter and wall thickness. The components were subjected to dynamic axial crushing kinetic energy equal to 1700 J. The numerical analysis was performed using Abaqus 6.14 software. The specific aim of the study was to determine the extent to which variable wall thickness affects the energy absorption capacity of the components under study. From the simulations, we have managed to establish a relationship between total energy absorption capacity and wall thickness. The results from the conducted analyses and the purpose-specific neural networks could provide the base for the future methodology for forecasting and optimisation of energy-absorbing systems.


2011 ◽  
Vol 213 ◽  
pp. 88-92 ◽  
Author(s):  
Qing Chun Wang ◽  
Hao Long Niu ◽  
Guo Quan Wang ◽  
Yu Xin Wang

Different aluminum foam filling lengths were used to increase the bending energy absorbing capacity of the popularly used hat sections. Bending energy-absorption performance of the thin-walled tubes was numerically studied by explicit non-linear software LS-Dyna. First empty hat section subjected to quasi-static bending crushing was simulated, then structures with different aluminium foam filling lengths were calculated, finally energy absorption capacity of these structures were compared. Calculation results showed that, the internal energy absorbed and mass specific energy absorption capacity of foam filled thin walled structures were increased significantly compared to the empty sections. The reason of the improvement was mainly due to the contact of the aluminium foam and the structure. Aluminium foam filling is a promising method for improving lateral energy absorbing capacity of thin-walled sections.


2016 ◽  
Vol 725 ◽  
pp. 162-167
Author(s):  
Si Cong Liu ◽  
Guo Xing Lu ◽  
Dong Wei Shu ◽  
Ying Xin Zhou ◽  
Zhi Ye Zhao

Rock movement caused by external explosion loading can damage the nearby tunnel or cavern.To avoid damage, energy absorbing bolts with high load-displacement and large energy absorptioncapacities are required. The deformation and friction of the bolt absorb energy during the rock movementand preventing the structure from damage. To maximize the energy absorption capacity in the limitedspace inside the borehole, we developed a new bolt that utilizes the friction and plastic deformation ofthe sleeve. To develop the new bolt, FE simulation in Abaqus was used to improve designs beforefabrication. Two prototypes of the new design was fabricated and tested by static pull test. The resultsshowed the bolts yielded in the desired way. The experimental results prove the new bolt is capable ofabsorbing large amount of energy and accommodating large displacement.


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