Opening behavior of PELE perforation on reinforced concrete target

Impact velocity(v0),target strength(fc)and target thickness(hc)are important factors affecting opening damage■of PELE penetration into RC target.In this paper,based on the three influence factors of v0,fc and hc,experimental and numerical simulation studies on PELE penetration into RC target were carried out.The study results show that:(1)Since interaction force(or penetration resistance)between projectile and target is positively correlated with v0 and fc,with the increase of v0 and fc,deformation mode of jacket is changed from small bending deformation to large bending deformation and then to curling deformation.Therefore,the variation of jacket deformation mode causes opening diameter of RC target to increase first and then to decrease.It is found that the two factors approximately satisfy a quadratic function relationship,respectively.(2)For PELE projectile penetrating RC targets with thickness of 80-400 mm,the opening diameter of six sets of RC targets grows from 240 to 500 mm,and hc with■approximately satisfy a linear relationship.(3)Based on the above study results,the relationship between two dimensionless parameters■and dimensionless opening diameter■was determined.Combined with the results of previous research,a dimensionless opening diameter model■was established.By tests verified,the test results are all within±10%error of the theoretical model,which verifies the accuracy of the model.

Effect of projectile parameters on opening behavior of PELE penetrating RC target

When a penetrator with enhanced lateral effect(PELE) impacts on a reinforced concrete(RC) target,the target is damaged with a large opening.An understanding of how PELE projectile parameters affect the opening dimension,is essential for effective design of the PELE projectile.In this study,under the condition that the impact velocity and target parameters(strength and thickness) were fixed values,the important influence factors of the PELE(jacket wall thickness B,jacket material strength Y1,filling material strength Y2 and angle of monolithic jacket θ) were determined by a dimensional analysis.Tests and simulations of the PELE penetrating the RC target were conducted to analyze the influence of these factors on opening diameter(D,an equivalent diameter under relative kinetic energy).Based on the test and simulation results,it is found that the influence of these factors B,Y1 and θ on the deformation mode of the jacket shows a similar trend:as values of the three factors decrease,the jacket deforms from small bending deformation to large one,and then to curling deformation.This causes the opening diameter to first increase with the decrease of these three factors,and then decreases.It is well known that the bending resistance of the jacket is related to these factors B,Y1 and θ.Therefore,a plastic limit bending moment(M0) of the jacket was quoted to characterize the influence of these factors on the bending deformation of the jacket and the opening diameter of the target.The influence factor Y2 causes D to first increase with the increase of Y2,and then decreases.A formula was developed to predict the opening diameter,whose influence parameters were considered in a dimensionless way.It has been shown that the dimensionless opening diameter D/d1 is dependent on two dimensionless parameters■ and■,where d1 and fc are the outer diameter of the projectile and the compressive strength of the target,respectively.

High production of β-glucosidase from a marine Aspergillus niger immobilized on towel gourd vegetable sponges

To produce β-glucosidase by consecutive batch fermentation, a marine Aspergillus niger was immobilized on a natural carrier, towel gourd vegetable sponges. The immobilized mycelia were 0.15 g/g carrier with the immobilized biomass percentage of over 95%. The immobilized mycelia possessed the long durability（22.5 days）. The maximum production occurred 1.5 day earlier by the immobilized mycelia than by the free mycelia. β-Glucosidase production of five consecutive batches was over 110 U/m L. At high salinity,the activity and stability of β-glucosidase from the marine A. niger increased remarkable. Immobilizing the marine A. niger on the novel natural carrier achieved the efficient production of β-glucosidase.