07-04-2011, 04:20 PM
PRESENTED BY
A.KRISHNA REDDY
[attachment=11876]
Effect of Various Geometric Parameters of The Multiliner Assembly on Explosively Formed Projectile
INTRODUCTION
Types of Missiles
Ballistic Missiles - Follows a sub-orbital ballistic flight path to a predetermined target. Used mainly for land attack missions.
Anti Ballistic Missiles – Designed to counter Ballistic Missiles.
The Missile
INTRODUCTION TO WARHEAD
The term warhead refers to the explosive material and detonator that is delivered by a missile, rocket, or torpedo.
The war head contains mainly three parts explosive, liner and adapter.
Explosive
An explosive material is a material that either is chemically or otherwise energetically unstable or produces a sudden expansion of the material usually accompanied by the production of heat and large changes in pressure (and typically also a flash and/or loud noise) upon initiation; this is called the explosion. An explosive charge is a measured quantity of explosive material.
Liner
The liner is one which forms into projectile that damages the target. The shape most commonly used for the liner is a cone, with an internal apex angle of 40 to 90 degrees.
Different apex angles yield different distributions of jet mass and velocity.
Other widely used shapes include hemispheres, tulips, trumpets, ellipses, and bi-conics; the various shapes yield jets with different velocity and mass distributions.
Adapter Ring
Adapter Ring is used for shape liner normally this is made up of tungsten material and fitted to the explosive cylinder.
Hyper mesh is used as a preprocessor for modeling and LS Dyna is used as a solver for simulation.
TYPES OF PROJECTILES
Scope of the project
This project is sponsored by PGAD,DRDO.
It consists of three phases
Single liner analysis
Multi liner analysis ( 5 liner and 7 liner) & validation
Shaped charges
Each phase covers
validation
Study of the effect of various geometric and material parameters on the liner shape and K.E
Optimization of parameters for better liner shape and Kinetic energy
First phase of the project was completed
This work covers the second phase of the project
methodology
The model is created using pro-e and imported to hypermesh for preprocessing.
The assembly consists of adapter, casing , linear and explosive
Shell elements are taken for adapter and liner. solid ALE elements are taken for explosive.
Single detonation point at the left centre of the explosive is considered for ignition.
Contacts are defined between liner and casing, explosive and liner, explosive and casing.
Required control cards are defined and the input file is given for LSDYNA.
Input file is simulated on LSDYNA by changing parameters to find the optimum results for attaining the velocity
Contact Definition
Liner and Explosive
*CONSTRAINED_LAGRANGE_IN_SOLID
Liner and Adapter
*CONTACT_AUTOMATIC_ONE_WAY_SURFACE_TO_SURFACE
Explosive and Air
*MULTI_MATERIAL
The variation of Velocity, Kinetic Energy, Projectile length and Projectile diameter of the projectile with the variation of liner thickness, liner external apex angle, explosive length is studied
FE Modelling
A.KRISHNA REDDY
[attachment=11876]
Effect of Various Geometric Parameters of The Multiliner Assembly on Explosively Formed Projectile
INTRODUCTION
Types of Missiles
Ballistic Missiles - Follows a sub-orbital ballistic flight path to a predetermined target. Used mainly for land attack missions.
Anti Ballistic Missiles – Designed to counter Ballistic Missiles.
The Missile
INTRODUCTION TO WARHEAD
The term warhead refers to the explosive material and detonator that is delivered by a missile, rocket, or torpedo.
The war head contains mainly three parts explosive, liner and adapter.
Explosive
An explosive material is a material that either is chemically or otherwise energetically unstable or produces a sudden expansion of the material usually accompanied by the production of heat and large changes in pressure (and typically also a flash and/or loud noise) upon initiation; this is called the explosion. An explosive charge is a measured quantity of explosive material.
Liner
The liner is one which forms into projectile that damages the target. The shape most commonly used for the liner is a cone, with an internal apex angle of 40 to 90 degrees.
Different apex angles yield different distributions of jet mass and velocity.
Other widely used shapes include hemispheres, tulips, trumpets, ellipses, and bi-conics; the various shapes yield jets with different velocity and mass distributions.
Adapter Ring
Adapter Ring is used for shape liner normally this is made up of tungsten material and fitted to the explosive cylinder.
Hyper mesh is used as a preprocessor for modeling and LS Dyna is used as a solver for simulation.
TYPES OF PROJECTILES
Scope of the project
This project is sponsored by PGAD,DRDO.
It consists of three phases
Single liner analysis
Multi liner analysis ( 5 liner and 7 liner) & validation
Shaped charges
Each phase covers
validation
Study of the effect of various geometric and material parameters on the liner shape and K.E
Optimization of parameters for better liner shape and Kinetic energy
First phase of the project was completed
This work covers the second phase of the project
methodology
The model is created using pro-e and imported to hypermesh for preprocessing.
The assembly consists of adapter, casing , linear and explosive
Shell elements are taken for adapter and liner. solid ALE elements are taken for explosive.
Single detonation point at the left centre of the explosive is considered for ignition.
Contacts are defined between liner and casing, explosive and liner, explosive and casing.
Required control cards are defined and the input file is given for LSDYNA.
Input file is simulated on LSDYNA by changing parameters to find the optimum results for attaining the velocity
Contact Definition
Liner and Explosive
*CONSTRAINED_LAGRANGE_IN_SOLID
Liner and Adapter
*CONTACT_AUTOMATIC_ONE_WAY_SURFACE_TO_SURFACE
Explosive and Air
*MULTI_MATERIAL
The variation of Velocity, Kinetic Energy, Projectile length and Projectile diameter of the projectile with the variation of liner thickness, liner external apex angle, explosive length is studied
FE Modelling