| As a amorphous thermal-plastic material, polycarbonate is also called"transparent metal"because of its excellent physical mechanical properties, especially the great impact resistance fairly similar with that of general metal materials. With the high transparence and impact strength, it could be applied in bulletproof glass, windshield, cockpit of airplane and so on. Therefore, studying the dynamic behavior of polycarbonate can provide technology support for the design of anti-impact structure using polycarbonate. Furthermore, for the design of warhead, the dynamic response of Penetrator during penetration target process and the main factor influencing the damage of projectile-body must be learned to design reasonable structure. As the body of warhead is usually made from high strength metal and its structure is very complicated, it is difficult to analysis that how its structure parameter influence the response during impacting process from current experiment, which put great difficulty on related theoretic analysis and model validation of computational simulations. By using transparent projectiles made from polycarbonate, we could observe the deformation and damaging process intuitively and understand the deformation and damaging rules. Moreover, the experimental data can be directly used in related theoretic analysis, checking and modifying models of computational simulations, studying the dynamic damage rules during impacting process, establish corresponding research method, which could provides certain theory base and technology support for the structure design of warhead.In this paper, based upon the analysis of the dynamic behavior of polycarbonate and Taylor impact response of polymeric materials, a series of experiments about the dynamic behavior in wide temperature and strain rate range were designed and performed. By analyzing the yield and plastic deformation mechanism, the yield constitutive model of amorphous polymeric materials was founded. By using polycarbonate as model material, impacting and penetrating experiments were carried out with polycarbonate projectiles. Combining photoplastic analysis, the influence rule of projectile on deformation or damage during impact process was provided. The main study content, methods and conclusions of this thesis are as follows:①The yield and plastic deformation mechanisms of amorphous polymers are very complicated. At different deformation stage and testing conditions there are different mechanisms such as the conformation changing,dislocation movement and kink pair propagation simultaneity existing in the deformation process at the same time. The molecule dynamic simulation result indicated that at elastic region, the system total potential energy and potential component irregularly fluctuated with the increase of strain. Close to the yield point, total potential energy and bond stretching energy abruptly increased and non-bond energy (Van der Waals energy) decreased. At steady plastic flowing region, each kind of energy had no apparently changing. At strain hardening stage, each kind of energy rose with the increase of stain. Analyzing the rapid snapshot on molecule chain during drawing process, it could be found that near yield region the internal deformation of materials was asymmetry. Interspaces appeared partially; after going into flowing region, molecules began to orientate.②Polycarbonate is sensitive against strain rate and temperature. Its yield stress increases with the increase of strain rate and decreases when temperatures rise. The dependence of yield stress against strain rate agrees with power-law function;Under glass transition temperature, the relationship of yield stress and temperature agree with polynomial Index equation. Below -75℃or above 100℃, there is a sudden change phenomena occurring. Yield can be looked as a kind of phase transition caused by stress, which could be equivalent to a thermodynamics process. The loading elastic modulus decreases with the rise of temperature and increases with the rise of strain rate. Cyclic loading and unloading compression experiment before yield point indicate that loading and unloading elastic modulus rise with the of increase cyclic times. Namely, cyclic loading and unloading will also cause the hardening of materials in viscoelastic region.③Under quasi-static tension conditions, the surface temperature begins to rise when approaching the yield point and rise fastest at strain softening stage. After going into steady plastic flowing region, the highest temperature tailing after the necking region has no obvious change,that is, the temperature reaches the highest after going into plastic region. Under dynamic compress, the temperature of the specimen has the h -ighest value in the center and become to decrease from center to out side. The temperature rising rate and the highest rising value depend on strain rate. At strain rate of 2624s-1,about 59% plastic work transforms into heat.④Before the rupture of polymeric materials, slippage of molecular chains firstly occurs which will cause partial deformation and result in the asymmetry of deformation. For single edge notched specimen before rupture, strain field reaches centerline position enduring loads along 45°～60°direction. For double edge notched specimen, the strain field will focuses to centerline position along the same direction. The rupture shape is related to the crack propagation rate.⑤A serials of PC projectile with different nosed shape and speed of 118m/s～278m/s were used to impact rigid target, the experiment result indicated that the load-time history of projectile can be obtained by measure the interface pressure while projectile impacting target. The impact pulse width mainly lies on the length of projectile. The wavform is smooth when the acuter the projectile-nose and waveform is vibrational when the projectile-nose approach flated-end. And the deformation of projectile is deeply affected by the shape of projectile-nose.⑥The Penetrating experiment of 3 kind of PC projectile with different nose shape at speed of 150m/s～250m/s across pure aluminums target and A3 steel target shows that the changing laws of PC projectile are similar with that of metal projectile. The overload coefficient of these 3 specimens decease in the following trend: flated-end projectile>hemisphere nosed projectile>truncated conical tip projectile. And the truncated conical tip projectile with large length-diameter ratio is suitable for Penetration.⑦The photoplastic analysis after impacting experiment shows that the interior deformation models are deferent according to different nose-shape. And the deformation model of projectile impacting rigid target is also different from that of Penetrating one. The changing of deformation model exists from nose to end of projectile. When a projectile impacts target, cylindrical regions endure smaller impact loading than nose region. Thus, materials with lower strength such as composite materials can be used for cylindrical regions to raise mass ratio between energetic materials and penetrator.⑧After thorough analyzed, the one-dimensional DSGZ model was transformed into three-dimensional and the model which was then embedded into huge general FEM program ABAQUS/Explicit as user subroutine. Not only the impacting and penetrating response of polycarbonate projectile was well simulated, but also immediacy apply to engineering analysis and practicability of DSGZ model is enhanced.
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