Study On Optimization Of Composite Tubular Energy Absorption System

A four-phase program to improve the specific energy absorbed by axially crushed composite collapsible tubular energy absorber devices was undertaken. In the first phase, the effects of trigged tube wall on the crushing behaviour were investigated. At this stage, triggered tubes were fabricated and crushed. The second phase is aimed at obtaining the best position for the triggered wall. The third phase focuses on the effects of material sizing in order to understand the influence of triggered wall Iength on the responses of composite circular tubes to the axial crushing load. The results from these three phases lead to the fourth phase. The objective of the 4t" phases was to optimise the shape geometry of the cross-section area to further improve tube energy absorption capability. The tubes were manufactured from woven roving glasslepoxy fabric and had the same lay-up providing a common laminate for comparison. The failure modes were observed and the specific sustained crushing loads were determined and compared against non-optimized tubes of the same lay-up. The importance of differentiating between initiation energy and propagation energy is shown, and a new parameter (energy capability index (ECI)) is proposed, as a useful measure for comparing crush behaviour of composite structures. The experimental results demonstrated strong potential benefits of optimizing the material distribution. The sizing and shape optimization of composite collapsible tubes exhibited a pronounced effect on their capability to absorb high specific energy under axial compressive load. For the effect of triggering it was that tubes (TN) observed to experience catastrophic failure mode during the post crush stage also displayed very poor energy absorption. Triggering a part of tube wall was very efficient in improving the energy absorption capacity of circular composite tubes. Accordingly tubes with triggered wall (T-tubes) exhibited highest energy absorption capacity compared with non-triggered tubes. They also experience stable post-crush region of loaddisplacement curves, which leads to high crashworthiness performance. It is also evident from the experimental results that change in the triggered wall aspect ratio significantly affected the energy absorption capability of tube with middle triggered wall (TM-tubes). Distinct differences were observed between the different aspect ratio, where TM tubes (i.e. tubes with triggered wall aspect ratio of 0.28) exhibited the highest energy absorption capacity. Different failure modes were observed for different triggered wall length ratios (Lt,/H). For the core tubes (TMC-), was observed that core presence markedly improved the energy absorption capacity of composite circular tubes. Among TMC- tubes, TMC3 tubes (i.e. tubes with core thickness of 3.35mm) displayed highest energy absorption capacity

Finite element analysis of sheet metal forming process

Minimization of response times and costs and maximization of the efficiency and quality in producing a product are imperative for survival in the competitive manufacturing industry. Sheet metal forming is a widely used and costly manufacturing process, to which these considerations apply. Aluminum sheet becomes favorable compare to steel regards to some improvement at aerodynamic designs, increased engine efficiency and fuel economy. Wide range of aluminum automotive product included doors, fenders, bumpers face bars, seat frames and roof panels have been produced. This paper was carried out to study the finite element (elastic-plastic) analysis of sheet metal forming process using the finite element software. LUSAS simulation was carried out to gain accurate and critical understanding of sheet forming process. Axisymmetry element mesh and plain strain element mesh were use incorporated with slideline features to model and study the sheet metal forming process. Simulation of elasticplastic behavior of aluminum sheet was carried out under non-linear condition to investigate sheet metal forming process

Thin-walled composite tubes using fillers subjected to quasistatic axial compression

It has been demonstrated that composites are lightweight, fatigue resistant and easily melded, a seemingly attractive alternative to metals. However, there has been no widespread switch from metals to composites in the automotive sector. This is because there are a number of technical issues relating to the use of composite materials that still need to be resolved including accurate material characterization, manufacturing and joining process. The total of 36 specimens have been fabricated using the fibre-glass and resin (epoxy) with a two different geometries (circular and corrugated) each one will be filled with five types of filler (Rice Husk, Wood Chips, Aluminium Chips, Coconut Fibre, Palm Oil Fibre) all these type will be compared with empty Tubes for circular and corrugated in order to comprehend the crashworthiness parameters (initial failure load, average load, maximum crushing load, load ratio, energy absorption, specific energy absorption, volumetric energy absorption, crushing force efficiency and crush strain relation) which are considered very sufficient parameters in the design of automotive industry parts. All the tests have been done using the "INSTRON Universal machine" which is computerized in order to simply give a high precision to the collection of the results, along with the use of quasi-static load to test and observe the behaviour of the fabricated specimens

Research summary on the processing, mechanical and tribological properties of aluminium matrix composites as effected by fly ash reinforcement

Fly ash is the main waste as a result of combustion in coal fired power plants. It represents about 40% of the wastes of coal combustion products (fly ash, boiler ash, flue gas desulphurization gypsum and bottom ash). Currently, coal waste is not fully utilized and waste disposal remains a serious concern despite tremendous global efforts in reducing fossil fuel dependency and shifting to sustainable energy sources. Owing to that, employment of fly ash as reinforcement particles in metallic matrix composites are gaining momentum as part of recycling effort and also as a means to improve the specifications of the materials that are added to it to form composite materials. Many studies have been done on fly ash to study composite materials wear characteristics including the effects of fly ash content, applied load, and sliding velocity. Here, particular attention is given to studies carried out on the influence FA content on physical, mechanical, and the thermal behavior of Aluminium-FA composites. Considerable changes in these properties are seen by fly ash refine-ment with limited size and weight fraction. The advantage of fly ash addition results in low density of composites materials, improvement of strength, and hardness. It further reduces the thermal expansion coefficient and improve wear resistance

Systematic development of an autonomous robotic car for fire-fighting based on the interactive design approach

Fire incidences are classed as catastrophic events, which mean that persons may experience mental distress and trauma. The development of a robotic vehicle specifically designed for fire extinguishing purposes has significant implications, as it not only addresses the issue of fire but also aims to safeguard human lives and minimize the extent of damage caused by indoor fire occurrences. The primary goal of the AFRC is to undergo a metamorphosis, allowing it to operate autonomously as a specialized support vehicle designed exclusively for the task of identifying and extinguishing fires. Researchers have undertaken the tasks of constructing an autonomous vehicle with robotic capabilities, devising a universal algorithm to be employed in the robotic firefighting process, and designing a fuzzy controller algorithm that can be used in all expected scenarios. The use of a fuzzy logic algorithm in this design demonstrates the usefulness of this system, all factors are involved in which cases are previously identified and taught, as well as the overall map of the premises have been uploaded so that the system can identify the exact place of the fire source, and two types of fire have also been examined. When the performance of the foam pump, water pump, and robotic car motors is compared to the data from the flam sensor, temperature sensor and GPS data, it demonstrates a high responsiveness in terms of applying the appropriate approach based on the type of fire due to the probable action for which the system has been trained. This will have the benefit of shortening the required process for fire extinguishment and using the appropriate fire extinguishing tools. This technology may be used to put out flames, deploy in different areas, and handle a variety of fire scenarios inside building

Experimental optimization of composite collapsible tubular energy absorber device

A four-phase program to improve the specific energy absorbed by axially crushed composite collapsible tubular energy absorber devices was undertaken. In the first phase, examining of the crushing behaviour of non-triggered tubes was carried out. The second phase is aimed at obtaining the best position for the triggered wall. The third phase focuses on the effects of material sizing in order to understand the influence of triggered wall length on the responses of composite circular tubes to the axial crushing load. The results of these three phases of the study contribute to the fourth whose objective is to optimize the shape geometry of the cross-section area to further improving in tube energy absorption capability. The experimental results demonstrated the strong potential benefits of optimizing the material distribution. The sizing and shape optimization of composite collapsible tubes exhibited a pronounced effect on their capability to absorb high specific energy under axial compressive load

A comparative analysis of experimental and numerical investigations of composite tubes under axial and lateral loading

Quasi-static tests are performed in order to determine the crash behavior of composite tubes. The specimens are made from woven fiber carbon/epoxy. The crash experiments show that the tubes crushed in a progressive manner from one end to the other of the tubes while delamination was - taking place between the layers. In the simulation works described in this paper the ANSYS explicit finite element code is used to investigate the compressive properties and crushing response of circular carbon tube subjected to static axial and lateral loading and the results are compared with the experimental work. To better understand the details of the crash process, thin multi layer shell elements are used to model the walls of the circular tube. Finally, the design optimization technique is implemented to find an optimum composite configuration that has the maximum failure load and absorbs the most energy. The crash performance of a carbon composite shell is compared with an optimum carbon tube from the experimental work. 2010, INSInet Publication.Scopu

Load-displacement behavior of glass fiber/epoxy composite plates with circular cut-outs subjected to compressive load

An experimental study of the behavior of woven glass fiber/epoxy composite laminated panels under compression is presented. Compression tests were performed on to 16 fiber-glass laminated plates with and without circular cut-outs using the compressed machine. The maximum load of failure for each of the glass-fiber/epoxy laminated plates under compression has been determined experimentally. A parametric study was performed as well to investigate the effects of varying the centrally located circular cut-out sizes and fiber angle-ply orientations on to the ultimate load. The experimental work revealed that as the cut-out size increases, the maximum load of the composite plate decreases. Also, it has been observed that cross-ply laminates possess the greatest ultimate load as compared to other types of ply stacking sequences and orientations

Experimental Investigation and Finite Element Analysis of Composite Conical Structures Subjected to Slip Loading

One of the main objectives of aircraft and automotive manufacturers is related to improvement of the crash behaviour of lightweight structures. The absorbed energy is an important parameter for the development of the vehicle passive security concept. An energy absorption device is a system that converts totally or partially kinetic energy into another form of energy during collision, which is required of an ideal energy absorbing material, is to have the capability of dissipating as much energy as possible per unit weight/ volume. The increasing demand of composite structures in wide range of engineering applications, structures made from composite materials offers important characteristics such as weight reduction, design flexibility and safety improvement. These composite structures provide higher or equivalent crash resistance as compared to their metallic counterparts and therefore find for its using in crashworthiness applications. Polymer composite materials have been introduced in the automotive industry primarily to reduce the overall weight of the vehicle, which results in energy economy and for better fuel cost. However, the current trend in producing lighter structures puts greater demands on the design of more efficient energy dissipating systems. The present study is essentially motivated by the increasing use of composite conical structures in crashworthiness applications. This study focuses on experimental and finite element investigation of glass fibre/epoxy and carbon fibre/epoxy composite conical shell were carried-out during the slipping of solid cone or composite cone into composite conical shell under radial and axial loading. This study has been divided into two main parts: Quasi-static methods and explicit integration methods (dynamic). These parts have been divided also into two sections concerning the problem solution. The first section is the finite element solution, which deals with composite conical shell in order to quantify the study and the second section is an experimental work. These methods used to improve the specific energy absorbed by crushed composite collapsible conical energy absorber devices were undertaken. LUSAS finite element analysis software was used for quasi-static method and ANSYS/LS-DYNA finite element software for dynamic explicit integration method were used to develop the models. Shell elements have been selected for the composite cones with the same wall thickness. Glass and carbon fibres have been used for the fabrication process of the specimens. The cone semi angles used were 4, 8, 12, 16 and 20 degrees. The cone dimensions were constant for all models as 100 mm height and 76.2 mm of bottom diameter. Load-displacement curve and deformation histories obtained from quasi-static work include the experimental and finite element results. These results obtained to calculate specific energy absorption and volumetric energy absorption. As well as others parameters, such as crush force efficiency, initial failure indicator, strain efficiency and failure modes. The results show that the cone angle, loading condition, fibre orientation and stacking sequence angle affects the load carrying capacity and energy absorption capacity of conical shell. On the other hand, the results obtained from finite element analysis for slipping crushed woven roving glass/epoxy composite conical shell by using the explicit integration methods was presented and discussed. The effects of geometrical on energy absorption characteristics and failure modes are investigated as well as the behaviour of structure subjected to dynamic loading. The kinetic energy and energy absorption capability was calculated and failure modes for non-linear dynamic analysis of structures in three dimension was identified. The load-time history curve and deformation history obtained from dynamic work also presented and discussed. The results show that the cone angle, fibre type and loading condition affect the load carrying capacity and energy absorption capacity of composite conical shell