Concept Body Intelligentized CAE Analyse-Modal Analyse

The design scheme of auto body structure needs to design and evaluate repeatedly at the early stage of concept design. The process needs to create finit element model repeatedly and decide the eventual scheme by comparing. The efficiency is low and the rate is slow in the method.The paper analyses the task and characteristic of concept design phase and exploits secondly by UG OPEN\API language on UG NX5. The new design tool that auto body structure concept design—VCD-ICAE(Vehicle Concept Design—intellectualized CAE) system is created and the new auto body concept design method is bring forward. The system can create quickly auto parameterized geometrical model of concept phase by template technology, then the parameter is designed and the pre-process is finished quickly, the system can analyses stiffness and modal, then the post view and produce report is created. This method analyses sensitivity of auto beam and panel and the parameter can be optimized. It can instruct and help the user to get satisfying design scheme. So the method quicken the process that auto body structure concept design phase and the time that auto body concept design phase is shorten and the difficulty of operation is reduced. The paper includes following contents:(1) The exploitation process by UG OPEN\API language in UG NX5 is studied. The alternant interface is created, the auto body structure analyse at concept design phase is finished quickly by parameter in interface.(2) The method of creating template and realize means is studied. The different template is created according to the different type auto. The different size and simple structure model is created by easy operation in interface. The method improves the speed of creating CAD model. The paper takes the three box car for example and the size data of three box is collected, The CAD model is created quickly by VCD soft. The simple model that similar with structure of three box car is created on the base of it by the local adjusting.(3) The method and approach of CAE model creating by VCD-ICAE soft is studied, The shape of section in detailed three box model is collected and the shape of section transfer to the data information and is saved section data-base of VCD, The welding spot information in the detailed model is collected and recorded in the template data-base. These parameters drive the model to create CAD model.(4) The simple model is solved by Nastran and free modal is analyzed and 10 level modal is calculated. One level torsional frequency is 24.85Hz,One level bending frequency is 39.26Hz。(5) The detailed three box CAD model is meshed by HyperMesh and the mesh is modified and adjusted. The CAE model is created and the free modal is analyzed. One level bending modal is 39.26Hz and torsional modal is 24.85Hz.(6) One level bending modal and torsional modal between simply model and detailed model is compared。(7) The sensitivity of simply model is calculated by VCD-ICAE soft and the influence that section thickness of beam and thickness of panel to one level bending modal and torsional modal is studied and the sensitivity is calculated.(8) The simple model is optimized ty VCD-ICAE soft. The auto weight makes optimized object and one level bending modal and torsional modal makes constraint, the panel makes design value and is optimized. The better scheme of auto body structure design is improved.This paper introduces the process that the second exploitation in UG NX5 by UG OPEN\API and VCD-ICAE soft system is created. The new auto body concept design method is put forward and the design cycle is shortened in concept phase. This method settles the base of auto intellectualized design in concept phase.