![](https://static.wixstatic.com/media/157719_8c0980cc0cd34f0ba9da68a5576a543e~mv2.jpg/v1/fill/w_288,h_193,al_c,q_80,usm_0.66_1.00_0.01,blur_2,enc_auto/157719_8c0980cc0cd34f0ba9da68a5576a543e~mv2.jpg)
SPG/MCSPG Two-stage Joint Analysis [Document]
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Stage 1: Joining process analysis
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Self-Piercing Riveting (SPR), Flow Drill Screwing (FDS)​, Anchoring
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Stage 2: Joint performance analysis with histories from stage 1
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Lap Shear (LS), Coach Peel (CP), Cross Tension (CT), Pullout​
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Stage 1 and stage 2 are independent analyses​
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New boundary conditions, materials, etc. are allowed in stage 2​
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LS-DYNA Keywords for Two-stage​ Joint Analysis
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All necessary keywords for a regular LS-DYNA SPG/MCSPG simulation
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Additional keywords for stage 1:
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*INTERFACE_SPRINGBACK_LSDYNA
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To output FEM histories to file "dynain"​
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*INTERFACE_SPG_1​ (no parameter)
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To output SPG histories to file "1234spg"​
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Additional keywords for stage 2:​
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*INCLUDE
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To include FEM histories from "dynain" from stage 1​
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​*INTERFACE_SPG_2 (no parameter)
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To read SPG histories from "1234spg0"
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Rename "1234spg" from stage 1 as "1234spg0"​​
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Numerical Example​
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SPR joining process and joint performance analysis​
![model.png](https://static.wixstatic.com/media/6fb9f6_abd54664f7c64c7d83c0b79d5cb7d569~mv2.png/v1/fill/w_81,h_50,al_c,q_85,usm_0.66_1.00_0.01,blur_2,enc_auto/model.png)
![eps_spr.gif](https://static.wixstatic.com/media/6fb9f6_274b24b88e6c4eb19fe60aea4befacd8~mv2.gif)
![yd_yf_drv.png](https://static.wixstatic.com/media/6fb9f6_77a75bc90b78466a8a8ece5cb0fa207f~mv2.png/v1/crop/x_6,y_0,w_487,h_422/fill/w_58,h_50,al_c,q_85,usm_0.66_1.00_0.01,blur_2,enc_auto/yd_yf_drv.png)
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.
![lps_iso.gif](https://static.wixstatic.com/media/6fb9f6_5b453287c0274a3cafb661eae8824808~mv2.gif)
![xf_lps2.png](https://static.wixstatic.com/media/6fb9f6_35bf5a50282746ba9953d4af004f92e5~mv2.png/v1/crop/x_6,y_4,w_490,h_385/fill/w_62,h_49,al_c,q_85,usm_0.66_1.00_0.01,blur_2,enc_auto/xf_lps2.png)
![peel_iso.gif](https://static.wixstatic.com/media/6fb9f6_2bdfcf21a94342cfb1f8a7c37f029fb9~mv2.gif)
![yf_cpl2.png](https://static.wixstatic.com/media/6fb9f6_96ba609b47424804bad9730f31e14f52~mv2.png/v1/fill/w_62,h_50,al_c,q_85,usm_0.66_1.00_0.01,blur_2,enc_auto/yf_cpl2.png)
![crt_iso.gif](https://static.wixstatic.com/media/6fb9f6_7beb62e48fd14649baaa811c92613364~mv2.gif)
![yf_crt2.png](https://static.wixstatic.com/media/6fb9f6_3f03398b65a54a27941107c818f7a337~mv2.png/v1/fill/w_62,h_49,al_c,q_85,usm_0.66_1.00_0.01,blur_2,enc_auto/yf_crt2.png)
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.