1、APPROVAL OF THE FORMING PROCESS BY FORMING SIMULATION(Volvo standard BCD 8008,073),The supplier shall always verify the forming process of the draw die with FE-analysis. A full incremental simulation shall be done. Onestep codes is not enough. All simulations shall be carried out in Autoform. In add

2、ition to Autoform any other software use is optional. Notations in the sim-file is presented in next pages.,1. General Information,Autoform settings & instructions,Feel free to use the comment field for information,This is the Volvo simulation number. It should not be in any simulation files sent fr

3、om supplier to Volvo. Supplier preferrably replaces this with their own simulation/job number.,This is the Volvo 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 Volv

4、o.,This is the Volvo project name. It should be in every simulation file sent from supplier to Volvo.,Filename for simulation files sent to Volvo shall contain Volvo part number,Use the Autoform equivalent drawbead in correct position. Geometrical drawbeads do not give the correct restraining force

5、(sensitive to Autoform Control parameter settings) and is impossible for Volvo to change in Autoform to check process window etc.,Volvo material data shall be used,Autoform settings & instructions,Normal Volvo settings, recommended,Wrinkles shall be turned off. This is today recommended by Autoform,

6、Autoform settings & instructions,Autoform settings & instructions,2.1 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 accepted, unles

7、s 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.,2.2 Requirements, sim

8、ulation,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 part. In some cases there are big differences in formability between

9、 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.,DP600HG-SSAB (V-1478) s = 472 Mpa b = 660 Mpa FGK0 = 21.5,DP600HG-Th

10、yssen (V-1478) s = 395 Mpa b = 613 Mpa FGK0 = 23.0,Examples, simulation resultsDifferent material supplier,2.3 Requirements, 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

11、 in the froming process can be allowed, but they should not be visible 10 mm from bottom. The failure (risc of cracks) must never 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

12、 % of the available press force.,Examples, simulation results,A-pillar reinforcement,10 mm from bottomAt bottom,Wrinkles ! NOT OK,It is still NOT OK !,Examples, simulation results,A-pillar reinforcement Risc of cracks,Failure,0.1 0.9,Formability,0.569 = OK !,0.796 = NOT OK !,0.64 = NOT OK !,Examples

13、, simulation results,A-pillar reinforcement Formability settings,These settings will give you yellow and red color for failures above 0.60 resp. 0.80,Formability diagram,Major strain,Minor strain,3. Approval of the simulation result,Before any simulation result may be sent to VCBC an agreement must

14、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 latest 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

15、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 approval 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 sim

16、ulation result has been recieved.,Tryout of the drawdie,It is important to use the same material inflow 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 ca

17、n only compare results between simulation and tryout if you have the same inflow of the sheet.,Springback calculation,Volvo 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 direct