1、VCBC/34402 Gran Gran 2004-05-10Volvo Cars Body Components1APPROVAL OF THE FORMING APPROVAL OF THE FORMING PROCESS BY FORMING SIMULATIONPROCESS BY FORMING SIMULATION(Volvo standard BCD 8008,073)(Volvo standard BCD 8008,073) The supplier shall always verify the forming process of the draw die with FE-
2、analysis. A full incremental simulation shall be done. Onestep codes is not enough. All simulations shall be carried out in Autoform. In addition to Autoform any other software use is optional. Notations in the sim-file is presented in next pages.1. General InformationVCBC/34402 Gran Gran 2004-05-10
3、Volvo Cars Body Components2Autoform settings & instructionsFeel free to use the comment fieldfor informationThis is the Volvo simulation number. It should not be in any simulation files sent from supplier to Volvo. Supplier preferrably replaces this with their own simulation/job number.This is the V
4、olvo Part Name. It should be in every simulation file sent from supplier to Volvo. This is the Volvo Part Number-Issue-Version. It should be in every simulation file sent from supplier to Volvo. This is the Volvo project name. It should be in every simulation file sent from supplier to Volvo. Filena
5、me for simulation files sent to Volvo shall contain Volvo part numberVCBC/34402 Gran Gran 2004-05-10Volvo Cars Body Components3Use the Autoform equivalent drawbead in correct position. Geometrical drawbeads do not give the correct restraining force (sensitive to Autoform Control parameter settings)
6、and is impossible for Volvo to change in Autoform to check process window etc.Volvo material data shall be usedAutoform settings & instructionsVCBC/34402 Gran Gran 2004-05-10Volvo Cars Body Components4Normal Volvo settings, recommendedWrinkles shall be turned off. This is today recommended by Autofo
7、rmAutoform settings & instructionsVCBC/34402 Gran Gran 2004-05-10Volvo Cars Body Components5Autoform settings & instructionsOnly geometries belonging to current simulation are allowed to be in sim-file. Older geometries should be deleted to avoid mistakes/confusions and to reduce filesizes (importan
8、t for EDI-transfer).VCBC/34402 Gran Gran 2004-05-10Volvo Cars Body Components62.1 Requirements, process The drawdepth shall be kept to a minimum Blanks with holes that are intended to crack during the draw are not accepted, unless a special agreement is made. Release cuts in the draw die are not acc
9、epted, unless a special agreement is made. The edge of the blank is not allowed to pass the draw radius. For outer panels it is never permitted to allow the edge of the blank to pass by the drawbead. For inner panels, it is not recommended to let the edge of the blank pass by the drawbead.VCBC/34402
10、 Gran Gran 2004-05-10Volvo Cars Body Components72.2 Requirements, simulation Generally the material flow should be controlled by drawbeads and not only by blankholder force. Volvo supplies the diemaker with material data for simulation. The diemaker must use the sent specific material data for every
11、 part. In some cases there are big differences in formability between material suppliers. (i.e. DP600 materials) (see example) Friction coefficient 0.15 must be used. Deviations from this must be explained. The simulations shall be carried out with a minimum of 5 layers and ”Fine” accuracy settings.
12、VCBC/34402 Gran Gran 2004-05-10Volvo Cars Body Components8DP600HG-SSAB (V-1478)s = 472 Mpab = 660 MpaFGK0 = 21.5DP600HG-Thyssen (V-1478)s = 395 Mpab = 613 MpaFGK0 = 23.0Examples, simulation resultsDifferent material supplierVCBC/34402 Gran Gran 2004-05-10Volvo Cars Body Components92.3 Requirements,
13、simulation results For outer panels, visible wrinkles are not accepted on the panel or its additional surfaces during the forming process. For inner parts small wrinkles early in the froming process can be allowed, but they should not be visible 10 mm from bottom. The failure (risc of cracks) must n
14、ever exceed 0.6 on the sheet. The thinning on outer panels must be higher than 2%. Skidmarks from feature lines on outer panels is not accepted. Press forces may not exceed 80 % of the available press force. VCBC/34402 Gran Gran 2004-05-10Volvo Cars Body Components10Examples, simulation resultsA-pil
15、lar reinforcement10 mm from bottomAt bottomWrinkles !NOT OK It is still NOT OK !VCBC/34402 Gran Gran 2004-05-10Volvo Cars Body Components11Examples, simulation resultsA-pillar reinforcementRisc of cracksFailure0.1 0.9Formability0.569 = OK !0.796 = NOT OK !0.64 = NOT OK !VCBC/34402 Gran Gran 2004-05-
16、10Volvo Cars Body Components12Examples, simulation resultsA-pillar reinforcementFormability settingsThese settings will give you yellow and red color for failures above 0.60 resp. 0.80VCBC/34402 Gran Gran 2004-05-10Volvo Cars Body Components13Formability diagramMajor strainMinor strainVCBC/34402 Gra
17、n Gran 2004-05-10Volvo Cars Body Components143. Approval of the simulation result Before any simulation result may be sent to VCBC an agreement must be made with the VCBC die process engineer or forming simulation engineer about sending the result.The supplier shall on request be able to send the la
18、test simulation files and CAD-data to VCBC at any time.Evaluation of the simulation result shall be done by the VCBC die process engineer together with the VCBC forming simulation engineer.Evaluation of the simulation must be carried out by VCBC before start of die design (before VKON) and a final a
19、pproval must be recieved by the supplier before casting.It is not permitted to cast any part of any die until written approval by VCBC of the simulation result has been recieved.VCBC/34402 Gran Gran 2004-05-10Volvo Cars Body Components15Tryout of the drawdieIt is important to use the same material i
20、nflow in the tryout as the result from the simulation.You should always try to get the same material inflow as the simulation result before you change any geometry inside the punch opening line.You can only compare results between simulation and tryout if you have the same inflow of the sheet.VCBC/3
21、4402 Gran Gran 2004-05-10Volvo Cars Body Components16Springback calculationVolvo has done several comparisons between simulated springback and springback in tryout.In some cases there have been good results and in other cases there have been not so good results.In most cases the direction of the springback is correct but the amount is not correct.Today Volvo can not demand the supplier to simulate the springback.It is ok for the supplier to use the simulated springback as long as all the criterions in the Volvo standard BCD 8008,073 is fullfilled.
