FRONTAL IMPACT FINITE ELEMENT MODELING TO DEVELOP FRP ENERGY ABSORBING POLE STRUCTURE

A. M. ELMARAKBI,K. M. SENNAH 한국자동차공학회 2006 International journal of automotive technology Vol.7 No.5

The aim of this paper is to contribute to the efficient design of traffic light poles involved in vehicle frontal collisions by developing a computer-based, finite-element model capable of capturing the impact characteristics. This is achieved by using the available non-linear dynamic analysis software “LS-DYNA3D”, which can accurately predict the dynamic response of both the vehicle and the traffic light pole. The fiber reinforced polymer (FRP) as a new pole’s material is proposed in this paper to increase energy absorption capabilities in the case of a traffic pole involved in a vehicle head-on collision. Numerical analyses are conducted to evaluate the effects of key parameters on the response of the pole embedded in soil when impacted by vehicles, including: soil type (clay and sand) and pole material type (FRP and steel). It is demonstrated from the numerical analysis that the FRP pole-soil system has favorable advantages over steel poles, where the FRP pole absorbed vehicle impact energy in a smoother behavior, which leads to smoother acceleration pulse and less deformation of the vehicle than those encountered with steel poles. Also, it was observed that clayey soil brings a slightly more resistance than sandy soil which helps reducing pole movement at ground level. Finally, FRP pole system provides more energy absorbing leading to protection during minor impacts and under service loading, and remain flexible enough to avoid influencing vehicle occupants, thus reducing fatalities and injuries resulting from the crash.

FRONTAL IMPACT FINITE ELEMENT MODELING TO DEVELOP FRP ENERGY ABSORBING POLE STRUCTURE

Elmarakbi, A.M.,Sennah, K.M. The Korean Society of Automotive Engineers 2006 International journal of automotive technology Vol.7 No.5

The aim of this paper is to contribute to the efficient design of traffic light poles involved in vehicle frontal collisions by developing a computer-based, finite-element model capable of capturing the impact characteristics. This is achieved by using the available non-linear dynamic analysis software "LS-DYNA3D", which can accurately predict the dynamic response of both the vehicle and the traffic light pole. The fiber reinforced polymer(FRP) as a new pole's material is proposed in this paper to increase energy absorption capabilities in the case of a traffic pole involved in a vehicle head-on collision. Numerical analyses are conducted to evaluate the effects of key parameters on the response of the pole embedded in soil when impacted by vehicles, including: soil type(clay and sand) and pole material type(FRP and steel). It is demonstrated from the numerical analysis that the FRP pole-soil system has favorable advantages over steel poles, where the FRP pole absorbed vehicle impact energy in a smoother behavior, which leads to smoother acceleration pulse and less deformation of the vehicle than those encountered with steel poles. Also, it was observed that clayey soil brings a slightly more resistance than sandy soil which helps reducing pole movement at ground level. Finally, FRP pole system provides more energy absorbing leading to protection during minor impacts and under service loading, and remain flexible enough to avoid influencing vehicle occupants, thus reducing fatalities and injuries resulting from the crash.

EXPERIMENTAL STUDY OF THE FLOW INDUCED BY A VEHICLE FAN AND THE EFFECT OF ENGINE BLOCKAGE IN A SIMPLIFIED MODEL

M. KHALED,M. GAD EL RAB,F. HACHEM,H. ELHAGE,A. ELMARAKBI,F. HARAMBAT,H. PEERHOSSAINI 한국자동차공학회 2016 International journal of automotive technology Vol.17 No.4

Fans are often tested without downstream blockage and, thus, the performance is considerably different when the fan is mounted in a vehicle as part of a cooling system and where high blockage effect is present downstream. The aim of the present work is to analyze by laser Doppler velocimetry LDV measurements the topology of the flow induced by a fan incorporated in a simplified underhood model reproducing engine blockage and to study the blockage effect of the engine positioning on the flow induced by the fan. The distance between the fan and the engine block affects the mean flow axial velocity U. The vertical velocity component W is greatly influenced by the variation of the distance between the fan and the engine block, both in magnitude and topology.

SIMPLE AND EFFECTIVE METHOD TO PREDICT THE OCCUPANT DYNAMIC RESPONSE UNDER SUDDEN IMPULSE LOADS

A. M. ELMARAKBI 한국자동차공학회 2006 International journal of automotive technology Vol.7 No.7

A mathematical model is developed in this paper to define the interaction between the occupant and vehicle passenger compartment and to predict the occupant dynamic response during a sudden impulse load. Two different types of occupants are considered in this study, child and adult occupants. The occupants are considered as lumped masses connected to the child seat and vehicle’s body masses by means of restraint systems. In addition, the occupant restraint characteristics of seat belt and airbag are represented by stiffness and damping elements. To obtain the dynamic response of the occupant, the equations of motion of the occupants during vehicle collisions are developed and analytically solved. The occupant's acceleration and relative displacement are used as injury criteria to interpret the results. It is demonstrated from the numerical simulations that the dynamic response and injury criteria are easily captured and analyzed. It is also shown that the mathematical models are flexible, useful in optimization studies and it can be used at initial design stage.

SIMPLE AND EFFECTIVE METHOD TO PREDICT THE OCCUPANT DYNAMIC RESPONSE UNDER SUDDEN IMPULSE LOADS

Elmarakbi, A.M. The Korean Society of Automotive Engineers 2006 International journal of automotive technology Vol.7 No.7

A mathematical model is developed in this paper to define the interaction between the occupant and vehicle passenger compartment and to predict the occupant dynamic response during a sudden impulse load. Two different types of occupants are considered in this study, child and adult occupants. The occupants are considered as lumped masses connected to the child seat and vehicle's body masses by means of restraint systems. In addition, the occupant restraint characteristics of seat belt and airbag are represented by stiffness and damping elements. To obtain the dynamic response of the occupant, the equations of motion of the occupants during vehicle collisions are developed and analytically solved. The occupant's acceleration and relative displacement are used as injury criteria to interpret the results. It is demonstrated from the numerical simulations that the dynamic response and injury criteria are easily captured and analyzed. It is also shown that the mathematical models are flexible, useful in optimization studies and it can be used at initial design stage.

CRASHWORTHINESS IMPROVEMENT OF VEHICLE-TO-RIGID FIXED BARRIER IN FULL FRONTAL IMPACT USING NOVEL VEHICLE'S FRONT-END STRUCTURES

A. M. ELMARAKBI,J. W. ZU 한국자동차공학회 2005 International journal of automotive technology Vol.6 No.5

There are different types of vehicle impacts recorded every year, resulting in many injuries and fatalities. The severity of these impacts depends on the aggressivety and incompatibility of vehicle-to-roadside hardware impacts. The aim of this paper is to investigate and to enhance crashworthiness in the case of full barrier impact using a new idea of crash improvement. Two different types of smart structures have been proposed to support the function of the existing vehicle. The work carried out in this paper includes developing and analyzing mathematical models of vehicle-to-barrier impact for the two types of smart structures. It is proven from analytical analysis that the mathematical models can be used in an effective way to give a quick insight of real life crashes. Moreover, it is shown that these models are valid and flexible, and can be useful in optimization studies.

CRASHWORTHINESS IMPROVEMENT OF VEHICLE-TO-RIGID FIXED BARRIER IN FULL FRONTAL IMPACT USING NOVEL VEHICLE'S FRONT-END STRUCTURES

ELMARAKBI A. M.,ZU J. W. The Korean Society of Automotive Engineers 2005 International journal of automotive technology Vol.6 No.5

There are different types of vehicle impacts recorded every year, resulting in many injuries and fatalities. The severity of these impacts depends on the aggressivety and incompatibility of vehicle-to-roadside hardware impacts. The aim of this paper is to investigate and to enhance crashworthiness in the case of full barrier impact using a new idea of crash improvement. Two different types of smart structures have been proposed to support the function of the existing vehicle. The work carried out in this paper includes developing and analyzing mathematical models of vehicle-to-barrier impact for the two types of smart structures. It is proven from analytical analysis that the mathematical models can be used in an effective way to give a quick insight of real life crashes. Moreover, it is shown that these models are valid and flexible, and can be useful in optimization studies.

ANALYSIS AND MODELING OF THE THERMAL SOAK PHASE OF A VEHICLE – TEMPERATURE AND HEAT FLUX MEASUREMENTS

M. KHALED,M. G. ELRAB,C. HABCHI,A. ALSHAER,A. ELMARAKBI,F. HARAMBAT,H. PEERHOSSAINI 한국자동차공학회 2015 International journal of automotive technology Vol.16 No.2

The thermal soak phase of a vehicle results from driving the vehicle at high load followed by shutting off the engine. The present work deals with the analysis and modeling of the thermal soak phase of a vehicle through temperature and heat flux measurements. Measurements are carried out on a passenger vehicle in wind tunnel S4 of Saint-Cyr-France. The underhood is instrumented by alsmot 120 surface and air thermocouples and 20 fluxmeters. Measurements are performed for three thermal functioning conditions, with the engine in operation and the front wheels positioned on the test facility with power-absorption controlled rollers. It was found that in thermal soak the temperature of certain components can increase by almost 80℃ (pre-catalyst) and that of air zones by alsmot 40℃ (crawl area). These components correspond to areas that heat up after stopping the engine for 3 to 24 minutes, depending on their position in the underhood and on the thermal operating point considered.