Dalian, China
Dalian, China

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Chen C.,Wuhan Naval University of Engineering | Zhu X.,Wuhan Naval University of Engineering | Hou H.,Wuhan Naval University of Engineering | Shen X.,Naval Unit No | Tang T.,Wuhan Naval University of Engineering
Harbin Gongcheng Daxue Xuebao/Journal of Harbin Engineering University | Year: 2012

The crevasse of warship structures subjected to close-range explosions of warheads was studied in this paper. Through model experiments, the deformation and rupture of a clamped large-scale square plate subjected to a close-range air blast were analyzed. On the basis of this analysis, a computational method which was used to determine the initial hole size was presented after employing the rigid-plastic assumption and energy density rule. Based on the conservation of energy, a theoretical model was developed to compute the ultimate sizes of the crevasses for clamped large-scale square plates subjected to close-range noncontact air blasts. Furthermore, calculations for the experiment were conducted. Results show that calculations by the theoretical model for test conditions correlate well with the experimental results both in terms of the sizes of the initial hole and the ultimate crevasse. The developed model could be employed to estimate the crevasse sizes of warship structures subjected to close-range noncontact airblasts in engineering.


Chen C.-H.,Wuhan Naval University of Engineering | Zhu X.,Wuhan Naval University of Engineering | Hou H.-L.,Wuhan Naval University of Engineering | Shen X.-L.,Naval Unit No | Tang T.,Wuhan Naval University of Engineering
Zhendong yu Chongji/Journal of Vibration and Shock | Year: 2013

To explore the influence of structural configuration on perforation-resistance of a composite armor system of warship topside, low velocity ballistic impact experiments were performed. The outer and inner composite armor systems of warship topside were simulated using homogeneous steel plates prefaced and backed with composite laminates, respectively. Failure modes and energy absorptions for the two types of combined targets were analyzed and compared with each other. Based on the experimental results, an equation was obtained to predict the residual velocities for the combined target consisting of front steel plates and composite backed armors. Results showed that the difference of the failure modes for the composite armors in the two types of combined targets mainly is the amount of sheared fibres; while the failure modes of the steel plates in the two types of combined targets are distinct due to the influences of composite armors; the combined target consisting of front steel plates and composite backed armors absorbs much more energy than the combined target consisting of front composite armors and steel backed plates does. It was shown that the theoretical predictions of the residual velocities agree well with the experimental results for the combined targets consisting of front steel plates and composite backed armors.


Chen C.-H.,Wuhan Naval University of Engineering | Zhu X.,Wuhan Naval University of Engineering | Hou H.-L.,Wuhan Naval University of Engineering | Shen X.-L.,Naval Unit No | Tang T.,Wuhan Naval University of Engineering
Dandao Xuebao/Journal of Ballistics | Year: 2012

In order to study anti-perforation mechanisms of warship topside interior-mounted composite armor(CA) and estimate the residual velocities of missile warheads after perforating CA to further design interior protective structures, low-velocity ballistic experiments were carried out for the interior-mounted CA, which was simulated by a steel plate at the front and a composite laminate at the back. Failure modes of the combined targets were analyzed. On the basis of the experimental results, a theoretical equation was developed to predict residual velocities of ball projectile perforating combined targets. Results show that front steel-plates of the combined targets are mainly destroyed by shear plugging, and the failure modes of composite backing armors are mainly fiber tensile-rupture. The theoretical predictions are in good agreement with experimental results in terms of residual velocities of projectiles.


Guo F.,Naval Unit No | Dong W.-C.,Wuhan Naval University of Engineering | Bi Y.,Wuhan Naval University of Engineering
Harbin Gongcheng Daxue Xuebao/Journal of Harbin Engineering University | Year: 2010

In order to investigate influencing factors to resistance reduction, the microbubble drag reduction in a gyroidal object was investigated numerically by using FLUENT 6.3 software. The relationship between the ratio of drag reduction and air injection parameters, such as velocity and angle of air injection, the bulk of the bubbles and the distribution of void fraction was discussed. The formation of the saturated air flow rate was also analyzed. It is shown that the microbubbles can reduce local friction resistance at maximum range of 80%, total resistance at maximum range of 30%, the resistance reduction ratio is mostly decided by the ratio of air injection velocity versus liquid velocity, and distributing of void fraction, is not closely related to the angle of air injection and the bulk of the bubbles at certain ranges. As air flow rate increases, the friction resistance reduces, but the viscosity pressure resistance increases, when the reduction magnitude of frictional resistance approaches the increase value of viscosity pressure resistance, the air flow rate comes to saturated value. The total resistance decreases as the air flow rate increases, when the air flow rate is less than the saturated value.


Chen C.-H.,Wuhan Naval University of Engineering | Zhu X.,Wuhan Naval University of Engineering | Hou H.-L.,Wuhan Naval University of Engineering | Shen X.-L.,Naval Unit No | Tang T.,Wuhan Naval University of Engineering
Baozha Yu Chongji/Explosion and Shock Waves | Year: 2012

To explore the deformation modes of warship structures subjected to close-range explosion of warhead and furnish experimental data, the deformation and damage modes of clamped large scale square plates under close-range blast loading were analyzed through model experiments. On the basis of the analysis, the failure strain of Q235 steel was obtained utilizing biaxial strain hypothesis and bulk equivalent theory via measuring the thinning rate of cracked petals. Based on the experimental results, a rupture criterion of structures subjected to localised blast loading was presented after employing rigid-plastic assumption and energy density rule. Moreover, predictions for experiments were made. The results show that the clamped plates exhibit three different deformation and damage modes with the increasing of the load intensity. The predictions by making use of the rupture criterion for test conditions correlate well with the experimental results.


Chen C.-H.,Wuhan Naval University of Engineering | Zhu X.,Wuhan Naval University of Engineering | Hou H.-L.,Wuhan Naval University of Engineering | Wang T.-Q.,Naval Unit No
Baozha Yu Chongji/Explosion and Shock Waves | Year: 2011

Low velocity ballistic impact experiments were carried out for composite armor system, which was combined with composite laminates at the front and homogeneous steel plates at the back. Failure modes and energy absorbing mechanism were analysed. Ballistic-resistance was compared between the composite laminates and homogeneous steel plates. Based on the experiments, an equation was obtained to predict the residual velocity for the perforation of combined targets according to failure modes. Results show that the unit area density energy absorbing of the composite laminates is far more greater than that of homogenous steel plates. Failure modes of the frontal composite armors of combined targets are mainly fabric tensile rupture. However, the failure modes of the steel backing plates are mostly petaling because of the influence of the frontal composite armors. It is shown that the theoretical predictions are in good agreement with experimental data.


Chen C.-H.,Wuhan Naval University of Engineering | Zhu X.,Wuhan Naval University of Engineering | Hou H.-L.,Wuhan Naval University of Engineering | Shen X.-L.,Naval Unit No | Tang T.,Wuhan Naval University of Engineering
Binggong Xuebao/Acta Armamentarii | Year: 2012

Low-velocity ballistic experiments were carried out to study the perforation-resistant mechanisms of warship topside composite armor system, which was simulated by composite laminates at the front and homogeneous steel plates at the back. Failure modes and energy absorbing mechanisms were investigated and the influence of the area density of front composite armors on total perforation resistance of combined targets was analyzed. Based on the experiments, an equation was obtained to predict the residual velocities in the case of low-velocity perforation of combined targets by hemispherical-nosed projectiles according to the failure modes of the targets. The results show that under low velocity perforation, combined targets mainly exhibit local damage. A few amounts of fiber at the impact side of front composite armor are sheared by the projectile. Failure modes of front composite armors are mainly fiber tensile rupture while for steel backing plates, failure modes are primarily petaloid damage. The whole energy-absorbing capability of combined targets increases with increasing the area density of front composite armors. It is shown that theoretical predictions coincide with the experimental results in terms of residual velocities.

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