Simulation of hybrid adhesive bonding processes

Transcription

1 Simulation of hybrid adhesive bonding processes SCA customer days 2015 Dr. Holger Fricke Ivo Fabian Neumann

2 Basics Simulation method Metal parts solid material form-locking and force-locking joint by metal forming process mechanical simulation FEM Lagrange Hybrid bonding adhesive fluid material Adhesive bonding liquide Fluid-dynamical simulation CFD Euler uni-directional fluid-structure-interaction (FSI) bi-directional material model Coupled-Euler-Lagrange (CEL) Abaqus material model

3 Basics Simulation method Metal Adhesive Elastic modulus, Poisson ratio, plastic deformation viscosity, viscos flow curve GEOMETRY KINEMATICS SIMULATION-MODEL

4 Clinch bonding Simulation of bonding process Verification Simulation/Experiment Punch side Matrix side HC340LA (1.0 mm) HC340LA (1.0 mm)

5 Clinch bonding Variation of materials and analysis of time steps Development of adhesive pockets in the region of the jointing point. radial flow of adhesive is suppressed because of contact of both metal sheets KST Alu/St > KST St/St HC340LA(1mm) + AlMg3(1mm) HC340LA(1mm) + HC430LA(1mm)

6 Clinch bonding Optimization of process kinematics punch hurries ahead punch stops at ~6 kn force for 1s timeframe for stop of punch must be optimized for each material combination optimized process decreases the amount of adhesive below the punch and the size of the adhesive pockets Punch hurries ahead the blank holder and stops Punch HC340LA (1.0 mm) Matrix HC340LA (1.0 mm)

7 0,144 mm 0,144 mm 0,147 mm Pictures Fraunhofer IWU 0,074 mm 0,103 mm 0,129 mm Clinch bonding Variation of metals and adhesives Influence of material pairing Influence of adhesive St/Alu Kinematics low viscosity high viscosity Standard 4mm/s 4mm/s Alu/St punch hurries adhead no stop 4mm/s High viscosity adhesive punch hurries adhead with stop undercut punch AlMg3 (1.0 mm) matrix AlMg3 (1.0 mm)

8 Clinch bonding Conclusion It is possible to run coupled fluid-structure interaction simulations Results of simulations fit well to experiments Simulations are able to describe the formation of adhesive pockets Simulations allow to optimize the process kinematics to avoid adhesive pockets

9 Rivet bonding Simulation of the hybrid bonding process Verification simulation/experiment Punch side Matrix side HC340LA (1.0 mm) HC340LA (1.0 mm)

10 Rivet bonding Adhesive pockets between the jointing points Simulation of parts with multiple mechanical hybrid joints Local model Export of adhesive flow and metal deformations global local Global model Jointing area is excluded Import of flow and deformations in multipoint hybrid joints

11 (mm) Rivet bonding Disk type samples Adhesive flow Metal deformations 0,3 Experiment Simulation 0,2 Disk diameter D = 50mm 0,1 0 Disk diameter D = 100mm Colors indicate velocities (0 15 mm/s) 0 0,5 1,0 1,5 (s)

12 Rivet bonding Cup profile (3 hybrid joints) x5 Contur plot of the adhesive flow velocities in horizontal direction [-10mm/s - 10mm/s] Mises stress (0-150 MPa) plastic deformation (0-0,003)

13 Rivet bonding Conclusion The Local Model describes one single joining process The Global Model describes a parts with multiple hybrid joints Calculated adhesive flow and deformation data is transferred from Local to Global model The modelling technique is able to handle complex shaped, industrial parts with multiple hybrid joints Comparison between simulation and experiments show good results

14 Hamming + adhesive bonding Simulation of the process Inner part HC340LA (1.0 mm) Outer part HC340LA (1.0 mm)

15 Hamming + adhesive bonding Failure pattern

16 Hamming + adhesive bonding Sensitivity analysis Variation Blank holder closed Final seam 1mm Reverence 1mm High difference in adhesive volume of hamming nose, but same filling level

17 Hamming + adhesive bonding Sensitivity analysis Variation Blank holder closed Final seam 1mm Reverence 1mm High difference in adhesive volume of hamming nose and high difference in filling level

18 Hamming + adhesive bonding Sensitivity analysis Variation Blank holder closed Final seam -1 Reverence +1 High decrease of filling level at angle -1

19 Hamming + adhesive bonding Sensitivity analysis Variation Blank holder closed Final seam Reverence 5 mm Very high increase of filling level using oil coated substrates

20 Hamming + adhesive bonding Formation process of air bubbles in the seam sealing Simulation of the thermal initiated curing process of the seam sealing (PVC-plastisol)

21 Hamming + adhesive bonding Conclusions The strong sensitivity of the hybrid hamming process is shown via simulation Some experimental results have been checked using experiments The strong sensitivity of the hybrid hamming process leads to strong variations of the filling level a large amount of known failure pattern. Possible corrosion! It is not possible to control the industrial hamm-bonding process as exact as needed Redesign of the process in needed (including polymer substitutes)

22 Industrial relevance of simulations of hybrid bonding processes Understanding the basic physical process => gain knowledge <= Identification of sensitive process parameters Identification of robust process windows Optimization of quality of products Calculation of material parameters (required rheologic behaviour of materials)

23 Meet again at Fraunhofer IFAM, Bremen, Germany