Design Optimization And Fe Analysis Of Automobile Bumper To Improve Energy Absorption

Abstract

Bumper is one of the main parts which are used as protection for passengers from front and rear collisions. The emission of harmful gases and fuel efficiency of vehicles are two important issues in these days. The best practice to improve fuel economy is to reduce the weight of vehicle parts. Bumper is one of the parts that have slightly more weight. This thesis was aimed to improve the crashworthiness of the existing automobile bumper to minimize crash injuries. The automobile bumper was analyzed for frontal collision. Based on the analysis results obtained from the existing model of automobile bumper then modifications are made by means of changing the geometry, using a composite material and optimizing the thickness of bumper. Then the modified bumper was analyzed under the same condition as the existing one. Software’s like that of CATIA and SOLIDWORKS was used for 3D modeling and LS-DYNA for simulation and FEM analysis. The result of the simulations shows that the weight of the carbon polyamide bumper is reduced as compared with the existing steel bumper by 9.7 kg or 52.5%, with this reduction in weight 42% increase in fuel economy; the energy absorption capability of carbon polyamide bumper is improved from the existing steel and aluminum bumper by 11.15% and 16.3% respectively and with this modification, the impact force is reduced from the existing steel bumper, which has 9.78 kN and aluminum alloy bumper, which has 4.10 kN to 1.86 kN. the crashworthiness parameter result analysis showed that the corrugated bumper geometry had a structural energy absorption (SEA), total energy absorption (TEA) and crush force efficiency (CFE) of 103.28J/kg, 911J and 77.99%, which is higher than the hallow bumper geometry of 102.4J/kg,847J and 65.83% respectively. In addition to that, as the thickness of carbon polyamide bumper reduced from 4mm to 3.5mm, 3mm and 2.5mm, deformation increased with a small rate from 13.5 mm to 16.7, 18.52 and 22.04 respectively, this does not mean that a bumper with less thickness is always better because more deformation means that there is probability of intrusion in to the vehicle main compartments. So it can be concluded that a bumper with 3mm thickness is the optimized model, the safety and crashworthiness of the automobile bumper was greatly improved without affecting the appearance and safety of the existing models.

Bumper Is One Of The Main Parts Which Are Used As Protection For Passengers From Front And Rear Collisions. The Emission Of Harmful Gases And Fuel Efficiency Of Vehicles Are Two Important Issues In These Days. The Best Practice To Improve Fuel Economy Is To Reduce The Weight Of Vehicle Parts. Bumper Is One Of The Parts That Have Slightly More Weight. This Thesis Was Aimed To Improve The Crashworthiness Of The Existing Automobile Bumper To Minimize Crash Injuries. The Automobile Bumper Was Analyzed For Frontal Collision. Based On The Analysis Results Obtained From The Existing Model Of Automobile Bumper Then Modifications Are Made By Means Of Changing The Geometry, Using A Composite Material And Optimizing The Thickness Of Bumper. Then The Modified Bumper Was Analyzed Under The Same Condition As The Existing One. Software?�?S Like That Of Catia And Solid works Was Used For 3d Modeling And Ls-Dyna For Simulation And Fem Analysis. The Result Of The Simulations Shows That The Weight Of The Carbon Polyamide Bumper Is Reduced As Compared With The Existing Steel Bumper By 9.7 Kg Or 52.5%, With This Reduction In Weight 42% Increase In Fuel Economy; The Energy Absorption Capability Of Carbon Polyamide Bumper Is Improved From The Existing Steel And Aluminum Bumper By 11.15% And 16.3% Respectively And With This Modification, The Impact Force Is Reduced From The Existing Steel Bumper, Which Has 9.78 Kn And Aluminum Alloy Bumper, Which Has 4.10 Kn To 1.86 Kn. The Crashworthiness Parameter Result Analysis Showed That The Corrugated Bumper Geometry Had A Structural Energy Absorption (Sea), Total Energy Absorption (Tea) And Crush Force Efficiency (Cfe) Of 103.28j/Kg, 911j And 77.99%, Which Is Higher Than The Hallow Bumper Geometry Of 102.4j/Kg,847j And 65.83% Respectively. In Addition To That, As The Thickness Of Carbon Polyamide Bumper Reduced From 4mm To 3.5mm, 3mm And 2.5mm, Deformation Increased With A Small Rate From 13.5 Mm To 16.7, 18.52 And 22.04 Respectively, This Does Not Mean That A Bumper With Less Thickness Is Always Better Because More Deformation Means That There Is Probability Of Intrusion In To The Vehicle Main Compartments. So It Can Be Concluded That A Bumper With 3mm Thickness Is The Optimized Model, The Safety And Crashworthiness Of The Automobile Bumper Was Greatly Improved Without Affecting The Appearance And Safety Of The Existing Models.