汽车驱动桥设计（含10张CAD图纸）.zip

Short communicationLightweight design of automobile component usinghigh strength steel based on dent resistanceYan Zhang*, Xinmin Lai, Ping Zhu, Wurong WangSchool of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200030, PR ChinaReceived 19 May 2004; accepted 14 September 2004AbstractLightweight and crashworthiness are two important aspects of auto-body design. In this paper, based on the shallow shell theory,the expression of dent resistance stiffness of double curvatured shallow shell is obtained under the concentrated load condition. Thecritical loads resulting in the local trivial dent in the center of the shallow shell is regarded as the important index for the lightweightof the automobile parts. This rule is applied to the lightweight design of bumper system by using high strength steel instead of mildsteel. The crashworthiness simulation of the lightweight part proves the validity of the lightweighting process.? 2004 Elsevier Ltd. All rights reserved.Keywords: High strength steel; Lightweight; Dent resistance1. IntroductionIn recent years, the retaining number of automobileshas been increasing steadily, which has impacted thesociety and human life greatly. Such situation leads tomany severe problems such as fuel crisis, environmentpollution. The international association of aluminumstated that petrol consumption can decrease by 810%with 10% reduction of car weight 2. Thus, automobilelightweight is a basic way to fuel saving.In order to reduce the automobile weight, there aretwo important methods 3: One, automobile parts areredesigned to optimize the structure. By using thinning,hollowing, minitype, and compound parts, car weightcan be reduced. The other, more and more lightweightmaterials, such as aluminum alloy, high strength steel,composite material, are widely used as lightweight mate-rials to replace the traditional materials like mild steel4. These materials could reduce the weight remarkably.Material replacement is generally more effective in auto-mobile lightweighting than structure modification. Withthe introduction of automobile safety legislation, crash-worthiness and safety should be considered as precondi-tions in lightweighting design of auto-body.High strength steel is widely used in automobilereplacing the traditional material of mild steel. Highstrength steel sheet can be used in auto-body to improvecomponents? impact energy absorption capacity andresistancetoplasticdeformation.Theautomobileweight can be reduced by use of high strength steel sheetof a thinner thickness to replace the mild steel sheet ofbody parts 1,3. Comparing with aluminum, magne-sium, and composite materials, high strength steel hasbetter economy in that its raw material and fabricationcost are cheaper. Besides, high strength steel can be di-rectly used in product line including forming, wielding,assembling, and painting. The operating cost can besaved since there is no need adjusting the whole line.Outside of automobile body, there are several sheetmetal Panels, most of which are shallow panels. Dentresistance is the ability to retain the shape against sunkendeflection and local dent under the external force. Dent0261-3069/$ - see front matter ? 2004 Elsevier Ltd. All rights reserved.doi:10.1016/j.matdes.2004.09.010*Corresponding author. Tel.: +86 21 62932964; fax: +86 2162933093.E-mail address: (Y. Zhang) and Design 27 (2006) 6468Materials& DesignResistance of automobile panels becomes an importantissue and quality criterion. Therefore, dent resistancestiffness of automobile panels should be tested and eval-uated in the process of panel design and manufacture.Some reported methods of testing are listed below 68:1. Test the displacement of sunken deflection fpunderfixed external force.2. Test the external force f to obtain fixed displacementof sunken deflection.3. Test the slope of forcedisplacement curve underexternal load.In this study, the second method will be used. The restof this paper is organized as follows: In Section 2, theexpression of dent resistance stiffness of double curva-tured shallow shell is obtained under the concentratedload condition based on the shallow shell theory. Thecritical load resulting in the local trivial dent in the centerof the shallow shell is regarded as the important evaluat-ing index for the dent resistance of the automobile parts.This rule is applied in Section 2 to the lightweighting de-sign of bumper system by using high strength steel in-stead of mild steel with crashworthiness simulation.2. Dent resistance analysis of double curvatured shallowshell2.1. Dent resistance stiffness analysis of shallow shellShell with mid surface can be characterized into threefeatures: thickness h, mid surface dimension L, curva-ture radius r, which satisfies h/r ? 1. When there existsh/L ? 1, the shell can be defined as thin shell. If L/r ? 1 is added besides the above two conditions, thethin shell is regarded as shallow shell 10.As Fig. 1 shows, the plane xy is the projecti