بررسي تجربي نفوذ پرتابه در اهداف چند لايه با جنس هاي متفاوت و چيدمان هاي مختلف

چكيده انگليسي :

Experimental study of penetration of projectile into the multilayer targets with different materials and layouts Ali Tavana a tavana@me iut ac ir August 10 2010 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisors Moradi Mehran Assistant Professor Email moradi@cc iut ac ir Ghayour Mostafa Associated Professor Email ghayour@cc iut ac ir Abstract Projectile penetration into the target is a complicated mechanical process that has been under consideration by researchers due to its military and non military applications The military applications include the design of structures that are resistant against projectile s penetration anti bullet armors design of light armor systems personal armors for the protection of police officers governmental authorities and martial individuals missiles and non military application like production of machines for transportation of dangerous materials strengthening the body of helicopters and aircrafts design of navies body protection of space crafts securing of head centers design of protective coverings against rays of nuclear reactors and etc In the above mentioned applications the impact loads due to external reasons like impact of the missiles or rackets or internal reasons like the increase in imposed pressure applied to these structures are of the most important applications of this subject The study of impact and penetration phenomenon is too intricate and includes many problems to deal with because it involves different parameters Some of these parameters are propagation of elastic and plastic waves mass and heat transfer work hardening friction hydrodynamic flow different fracture mode the effect of geometry of impacting materials resistance and the density of impacting materials and other parameters In the recent fifty years many scientist have worked in this field They have studied this complicated phenomenon with different analytical and experimental methods together with perfuming numerical simulations Therefore the importance of this subject causes this project to survey the penetration process both experimentally and numerically In this thesis the penetration of a projectile with noise hemispherical into the targets with three adjacent layers without air gap with different arrangement and materials is been studied The targets are circular plates with the diameter of 240mm and the material chosen is copper ofhc and AL1100 and the material of projectile itself is silver steel that is hardened to 50 Rockwell and the weight of projectile is 11 30g For implementing the experiments a single step gas gun is used The targets are arranged in three layers and without air gap The thickness of each layer is 1mm While defining ballistic limit for the projectile target system the effect of layers arrangement sequence and material in their ballistic operation is pursued The result of the experiments showed that among eight possible different arrangement if the aluminum and copper be arranged in sequence that the aluminum plates harder material are placed in the two first layers and CU softer material is placed in the third layer the resistance against penetration will have the maximum value Key Words Penetration Projectile Gas gun Ballistic limit velocity Aluminium Copper

توانا، علي

بررسي تجربي نفوذ پرتابه در اهداف چند لايه با جنس هاي متفاوت و چيدمان هاي مختلف

تفنگ گازي , سرعت حدبالستيك , ميزان جذب انرژي هدف