scholarly journals Study on Combined Energy Absorption Support for Rockburst Disaster Control in Tunnelling

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Liang Kuang ◽  
Gang Wang ◽  
Wenge Qiu ◽  
Lun Gong ◽  
Zhiqiang Feng ◽  
...  
Keyword(s):  
Energy Storage ◽  
Energy Absorption ◽  
Control Mechanism ◽  
Impact Force ◽  
Steel Tube ◽  
Steel Pipes ◽  
Loading Tests ◽  
Energy Absorbing ◽  
Disaster Control ◽  
The Impact

In order to better realize the rockburst disaster control mechanism and approach, the rockburst response of concrete blocks with different energy absorption levels under different energy storage conditions was observed and analyzed by loading tests. The occurrence and control mechanism of rockburst were explored from the perspective of energy aggregation and energy dissipation. On this basis, a combined energy absorption support system of concrete-filled steel tube frames and hollow steel pipes for rockburst disaster control was designed, and the effectiveness of the system was verified by numerical simulation and field tests. The results of loading tests show that the failure mode of the specimens changes from static failure to dynamic burst under energy storage loading. The occurrence of rockburst is inevitable when the energy supply is sufficient, but the disaster can be reduced or eliminated by strengthening constraints and improving energy-absorbing capacity to transform rockburst into large deformation. The combined structure consists of the hollow steel pipes being energy-absorbing part and the concrete-filled steel tube frames being strong confinement part was proposed to control rockburst disaster in tunnel support. The numerical analysis on the dynamic response of the support under strong rockburst impact shows that the hollow steel pipes effectively reduced the impact force on the concrete-filled tube frames, and accordingly, the deformation of the entire support system decreased. Given the condition that the hollow steel pipes be able to absorb all the impact energy during deformation, the smaller the strength of the hollow steel pipe is, the smaller the impact force and the displacement is. The combined energy absorption support provides an effective solution for rockburst disaster management in tunnels with strict clearance requirements.

Dynamic Responses of Buried Pipelines Under Impact Loading Caused by Landslide

2012 ◽  
Vol 204-208 ◽  
pp. 3476-3479 ◽  
Author(s):  
Xiu Xing Zhu ◽  
Shi Feng Xue ◽  
Xing Hua Tong ◽  
Chuan Qi Liu
Keyword(s):  
Impact Loading ◽  
Impact Force ◽  
Large Diameter ◽  
Influence Factors ◽  
Dynamic Responses ◽  
Thin Wall ◽  
Buried Pipelines ◽  
Steel Pipes ◽  
Mountainous Regions ◽  
The Impact

Cases of pipeline damage caused by landslide are common in coastal or mountainous regions, where the design of buried pipelines should be improved in order to reduce the risk of damage or failure. Dynamic responses of large diameter thin wall steel pipes under impact loading were analyzed using a nonlinear contact model of pipe-soil coupling in this paper. Several influence factors were studied, such as the impact velocity of rockfall, buried depth of pipeline, ratio of diameter to thickness and style of soil. The results show that an ellipsoid induces much more impact force than a sphere which has the same volume, and the larger one in volume have greater impact force for two spheres. Dangerous compressive areas of pipeline occupy 1/6 of the whole area, so the pipelines subject to landslide occur local failure. Based on results, some useful suggestions for the design of pipelines in landslide region are given

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.

IMPACT FORCE RESPONSE OF SHORT CONCRETE FILLED STEEL TUBULAR COLUMNS UNDER AXIAL LOAD

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1361-1368 ◽  
Author(s):  
GOUPING REN ◽  
ZHU LI
Keyword(s):  
Impact Force ◽  
Time History ◽  
Material Model ◽  
Critical Energy ◽  
Steel Tube ◽  
Peak Force ◽  
Impact Speed ◽  
Tubular Columns ◽  
Unitary Model ◽  
The Impact

The impact test on short concrete filled steel tubular column was conducted through DHR-9401 dropped hammer tester. Based on analysis on recorded time-history curve of impact force, the relations of impact force with respect to confining effect coefficient and impact speed are obtained. So are done that of the impact duration. By use of ANSYS/LS-DYNA, values of impact peak force in relation with those of impact speed were computed in the case of unitary material model and composite material model respectively. The simulation results show that peak force-speed curve of unitary model has better description of test data than that of composite one. Critical energy is found to increase linearly with the steel ratio when steel tube and concrete remain unchanged.

Study on Ballistic Energy Absorption of Laminated and Sandwich Composites

2006 ◽  
Vol 306-308 ◽  
pp. 739-744 ◽  
Author(s):  
Xiao Dong Cui ◽  
Tao Zeng ◽  
Dai Ning Fang
Keyword(s):  
Energy Absorption ◽  
Impact Response ◽  
Sandwich Composite ◽  
Sandwich Composites ◽  
Ballistic Resistance ◽  
Honeycomb Sandwich ◽  
Honeycomb Sandwich Composite ◽  
Improved Model ◽  
Energy Absorbing ◽  
The Impact

The impact response and energy absorbing characteristics of laminated, foam sandwich and honeycomb sandwich composites under ballistic impact have been studied in this investigation. An improved model is proposed in this paper to predict the ballistic property of the laminated composites. In this model, the material structures related to fiber lamination angles are designed in terms of their anti-impacting energy absorption capability. The ballistic limit speed and energy absorption per unit thickness of the three composites under different conditions are calculated. It is shown that honeycomb sandwich composite has the best ballistic resistance capability and energy absorption property among the three composites.

Experimental analysis on the axial crushing and energy absorption characteristics of novel hybrid aluminium/composite-capped cylindrical tubular structures

2019 ◽  
Vol 233 (11) ◽  
pp. 2234-2252 ◽  
Author(s):  
A Praveen Kumar
Keyword(s):  
Energy Absorption ◽  
Specific Energy ◽  
Cylindrical Tube ◽  
Tubular Structures ◽  
Aluminium Composite ◽  
Specific Energy Absorption ◽  
Cylindrical Tubes ◽  
Impact Crushing ◽  
Energy Absorbing ◽  
The Impact

In recent years, aluminium-composite hybrid tubular structures, which combine the stable and progressive plastic deformation of the aluminium metal with light-weight composite materials, are obtaining increased consideration for meeting the advanced needs of crashworthiness characteristics. This research article presents the experimental outcomes of novel aluminium/composite-capped cylindrical tubes subjected to quasi-static and impact axial loads. The influence of various capped geometries in the aluminium segment and three different fabrics of the composite segment in the cylindrical tube are investigated experimentally. The outcomes of the impact crushing test are also correlated with the quasi-static results of the proposed aluminium/composite-capped cylindrical tubes. The overall outcomes revealed that the crashworthiness characteristics of crushing force consistency and specific energy absorption of the aluminium-composite hybrid tubes are superior to those of the bare aluminium tubes. When the glass fabric/epoxy composite is wrapped to aluminium cylindrical tubes, the specific energy absorption increases about 23–30%, and the wrapping of hybrid glass/kenaf fabrics increases the specific energy absorption of almost 40–52%. Such a hybrid tubular structures would be of huge prospective to be used as effective energy-absorbing devices in aerospace and automotive applications. A further benefit of the composite-wrapping approach is that the composite might be retro-fitted to aluminium tubes, and the energy absorption capability is shown to be significantly enhanced by such utilization.

Influence of the Cross Section Shape on Energy Absorbing Component of Bumper Subjected to Low Speed Crash

2013 ◽  
Vol 477-478 ◽  
pp. 3-6
Author(s):  
Yan Jie Liu ◽  
Lin Ding
Keyword(s):  
Energy Absorption ◽  
Cross Section ◽  
Peak Load ◽  
Low Velocity Impact ◽  
Fe Model ◽  
Cross Section Shape ◽  
Section Shape ◽  
The Cross ◽  
Energy Absorbing ◽  
The Impact

Energy absorbing component of bumper equipped at the front end of a car, is one of the most important automotive parts for crash energy absorption. It usually was made a mental thin walled tube. In the paper, automobile energy absorbing component at low-velocity impact was studied by using Finite Element Method. The FE model of the tube was builded by comparing the five cross section shape . Results show that the impact peak load and maximum energy absorption have certain effect to energy-absorbing component with different the cross section shape.

Characterization of Polyethylene Foams under Compressive Impact Loading

2005 ◽  
Vol 480-481 ◽  
pp. 513-518 ◽  
Author(s):  
J.L. Ruiz-Herrero ◽  
Miguel A. Rodríguez-Pérez ◽  
Jose A. de Saja
Keyword(s):  
Energy Absorption ◽  
Impact Loading ◽  
Energy Impact ◽  
Optimum Energy ◽  
Rapid Loading ◽  
Protected Object ◽  
Absorbing Material ◽  
Energy Absorbing ◽  
The Impact

It has long been recognized that the mechanical behaviour of materials under conditions of rapid loading and impact differs significantly from that under static load application [1].These differences are specially important for those materials as polymeric foams used as low energy impact absorbing materials[2]. An optimum energy absorbing material needs to dissipate the kinetic energy of the impact while keeping the force on it below some limit, thus resulting in a no-dangerous deceleration of the protected object[3]. The mechanical properties at room temperature of six polyethylene foams with closed cells and different densities have been evaluated in purely compressive impact loading conditions. The energy absorption characteristics have been evaluated through different parameters as the peak of deceleration, the load transmitted, the maximum strain and the impact time. The peak of deceleration is used to obtain the cushion diagrams at five different heights, useful to design energy absorption structures.

An Assessment of the Impact Performance of Bonded Joints for Use in High Energy Absorbing Structures

1985 ◽  
Vol 199 (2) ◽  
pp. 121-131 ◽  
Author(s):  
J A Harris ◽  
R D Adams
Keyword(s):  
Energy Absorption ◽  
Joint Strength ◽  
High Energy ◽  
Lap Joints ◽  
Impact Performance ◽  
Single Lap Joints ◽  
Epoxy Adhesives ◽  
Energy Absorbing ◽  
The Impact ◽  
Spot Welded

Using an instrumented impact test, the strength and energy absorption of bonded single lap joints have been measured for single lap joints with four epoxy adhesives and three aluminium alloy adherends. Compared with the static values, joint strength is not significantly affected by the high loading rates. Energy absorption is large when joint strength is sufficient for plastic deformation to occur in the adherends prior to failure, which is only the case for certain adherend/adhesive combinations. Spot welded joints are shown to be inferior in performance in the tests. The effect of loading rate on bonded joint strength has been analysed using a non-linear finite element method, from which predictions of joint strength in keeping with the experimental results have been obtained. Crush tests carried out on open-ended cylinders have been used to simulate the impact behaviour of an energy absorbing structure. Similar performance was observed for cylinders with either bonded or spot welded longitudinal seams, although the large deformations in the crumple zones led to some debonding and weld fracture.

scholarly journals Energy Absorption Mechanism and Its Influencing Factors for Circular Concrete-Filled Steel Tubular Members Subjected to Lateral Impact

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4652
Author(s):  
Luming Wang ◽  
Yanhui Liu ◽  
Lang Yang ◽  
Nan Xu ◽  
Shichun Zhao
Keyword(s):  
Energy Absorption ◽  
Steel Tube ◽  
Absorption Characteristic ◽  
Lateral Impact ◽  
Absorption Process ◽  
Tube Material ◽  
Absorption Mechanism ◽  
Concrete Material ◽  
Important Indicator ◽  
The Impact

The energy absorption characteristic of steel tube material and concrete material is an important indicator to reflect the impact resistance of circular concrete-filled steel tubular (CFST) members. In order to efficiently simulate the material energy absorption of the steel tube and concrete under lateral impact, a nonlinear finite element model considering the material strain rate of the circular CFST member was established and validated based on the drop weight tests. Then, the energy absorption mechanism of circular CFST members subjected to lateral impact was investigated including the revelation of the energy absorption process and the determination of the energy absorption distribution for the steel tube material and concrete material, which are obtained respectively based on the comprehensive analysis of dynamic response and innovative establishment of the segmented numerical model. In addition, the influence of impact momentum on energy absorption process and the effect of impact location on energy absorption distribution are further carried out. The observations of this investigation can provide reference for the anti-impact design and damage reinforcement of circular CFST members subjected to lateral impact.

INVESTIGATION OF REGULARITIES OF PLASTIC DEFORMATION OF HOLLOW STEEL PROFILES BY COMPRESSION

2019 ◽  
Vol 6 (3) ◽  
pp. 22-26
Author(s):  
Alla Alexandrovna Gerasimova
Keyword(s):  
Plastic Deformation ◽  
Energy Absorption ◽  
Cross Sections ◽  
Mechanical Energy ◽  
Steel Pipes ◽  
Power Characteristics ◽  
Safety And Reliability ◽  
Maximum Effort ◽  
Control Of Parameters ◽  
Energy Absorbing

The article studies the kinematics of elastic-plastic deformation of hollow steel profiles. The aim of the work was to improve the power characteristics of the processes of plastic deformation of energy-absorbing structural elements of the hollow profile of vehicles and to increase the passive safety and reliability of equipment. Finite element modeling of kinematics of processes with control of parameters of energy absorption of steel pipes of various cross sections was carried out. The results of virtual studies of bending and precipitation at the end of a number of hollow profiles in the form of pipes of different sections have shown ample opportunities to control the process of mechanical energy absorption by selecting the design of pipes, control the results of modeling the absorbed energy and the maximum effort on the indicator diagram of the deformation process.

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