Multi-stage Explosions with ALE Method

[Ameen Topa]

Hello everyone,

I am doing the analysis of multiple blast analysis on buried structures. The slab is 1 m under the soil and the TNT is located on the surface of the soil. 

I need a way to carry the deformation of the soil (ALE) from the first simulation to the second one where I can add a second TNT charge at a different location. Using the ALE mapping, the information of the structure will not be carried to the second simulation. 

Any hints of this matter would be highly appreciated.

Sincerely,

Ameen

 

[l...@schwer.net]

Ameen –

 

I am not 100% sure what you want to simulate?

 

1\ Your second TNT detonation would NOT include the slab?

 

2\ Have you thought of using the parameter “LT -- Lighting time for detonation point,” on keyword *INITIAL_DETONATION to have a single model with two TNT charges that detonate at different times and locations?

 

                --len

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[Ameen Topa]

Hi Len,

Thanks for your response. 

1 - The second TNT detonation will include the slab. The attached photo below illustrates what I am trying to do. After the first explosion, there will be a crater. The second TNT charge is to be located in the crater

2 - I have tried using this by adding two TNT charges in one single simulation. But when the blast pressure from the first TNT charge reaches the second charge, the second one explodes as well.  

Regards,
Ameen Topa

        

[l...@schwer.net]

Thanks Ameen for the explanation and especially the illustrations.

 

In your two charge single simulation, did you set BETA=2 on the *MAT_HIGH_EXPLOSIVE_BURN keyword? If not, that explains the detonation of the second TNT charge when the pressure wave arrived at that location.

 

“If the beta burn option is used, BETA = 1.0, any volumetric compression will cause detonation”  from the User Manual

 

 

As a possible alternative, I suggest you consider a Full Restart using *STRESS_INITIALIZATION for the second TNT charge; see the User Manual section on “Restart Input Data.” This might be a bit tricky and I would construct a simple model for testing of the procedure.

 

                --len

 

From: Ameen Topa <engine...@gmail.com>
Sent: Thursday, January 15, 2026 5:13 PM
To: L...@schwer.net
Cc: LS-DYNA2 <ls-d...@googlegroups.com>
Subject: Re: [LS-DYNA2] Multi-stage Explosions with ALE Method

 

Hi Len,

Thanks for your response. 

1 - The second TNT detonation will include the slab. The attached photo below illustrates what I am trying to do. After the first explosion, there will be a crater. The second TNT charge is to be located in the crater

 

2 - I have tried using this by adding two TNT charges in one single simulation. But when the blast pressure from the first TNT charge reaches the second charge, the second one explodes as well.  

 

Regards,
Ameen Topa