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SPG/MCSPG Two-stage Joint Analysis [Document]

  • Stage 1: Joining process analysis

    • Self-Piercing Riveting (SPR), Flow Drill Screwing (FDS)​, Anchoring

  • Stage 2: Joint performance analysis with histories from stage 1

    • Lap Shear (LS), Coach Peel (CP), Cross Tension (CT), Pullout​

  • Stage 1 and stage 2 are independent analyses​

    • New boundary conditions, materials, etc. are allowed in stage 2​


LS-DYNA Keywords for Two-stage​ Joint Analysis

  • All necessary keywords for a regular LS-DYNA SPG/MCSPG simulation

  • Additional keywords for stage 1:


      • To output FEM histories to file "dynain"​

    • *INTERFACE_SPG_1​ (no parameter)

      • To output SPG histories to file "1234spg"​

  • Additional keywords for stage 2:​

    • *INCLUDE

      • To include FEM histories from "dynain" from stage 1​

    • *INTERFACE_SPG_2 (no parameter)

      • To read SPG histories from "1234spg0"

        • Rename "1234spg" from stage 1 as "1234spg0"​​


Numerical Example​

  • SPR joining process and joint performance analysis


Applied force

Stage 1: Joining process analysis

In the SPR joining process, material separation and mechanical locking can be reasonably captured by the SPG/MCSPG method in stage 1 analysis. The force applied on the tool can be properly predicted by the numerical methods as well.


Stage 2: joint performance analysis (lap shear, coach peel, cross tension)

In stage 2, the histories (e.g. effective plastic strain, stress and deformed shape) from stage 1 are used as initial conditions. With the new added loading arms, various SPR joint strengths can be evaluated while only one simulation is performed for stage 1 analysis. Here, lap shear, coach peel and cross tension tests are analyzed in the second stage SPG/MCSPG simulation and the corresponding joint strengths are obtained effectively.

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