Theoretical and numerical research on the dynamic launch response of carbon fiber composite cartridges

Understanding the dynamic response of composite material cartridges during the firing process is of great significance for improving their reliability and safety.A theoretical model describing the dynamic response of composite material cartridges is established based on the thick-walled cylinder theory and rate-dependent constitutive model of composite materials.The correctness of the theoretical model is validated through finite element simulations of cartridge deformation.The influence of chamber pressure and cartridge wall thickness on the cartridge's deformation process and stress distribution is analyzed.The results indicate that the primary deformation of composite material cartridges inside the chamber is elastic deformation.Compared to metal cartridges,composite material cartridges require higher pressure for touching-chamber and are more prone to developing gaps after unloading to ensure smooth extraction.During the deformation process,the touching-chamber behavior of the cartridge can improve the stress distribution.Under the same chamber pressure,the touching-chamber behavior can reduce the circumferential stress by approximately 30%.The inner wall surface of the cartridge is a critical area that requires attention.The touching-chamber behavior can be facilitated by appropriately reducing the cartridge wall thickness while ensuring overall strength.This study can provide guidance for the optimization design of composite material cartridges.

DYNAMIC CHARACTERISTICS OF LARGE FLOW RATING ELECTROHYDRAULIC PROPORTIONAL CARTRIDGE VALVE

A kind of cartridge servo proportional valve is discussed, which can be used for controlling large flow rate with high performance. By analyzing the structure principle of the valve, the transfer fimction of the valve is derived. With the transfer function, some structure elements that may affect its performance are investigated. Through the numerical simulation and test study, some principles of optimality and effective methods for improving the dynamic performance of the valve are proposed. The test results conform to the results of the theoretical analysis and simulation, which proves the correctness of the study and simulation works. The paper provides theoretical basis for engineering applications and series expanding design works

Fractal Dimension of Pore Structure of Combustible Cartridge Cases

A fractal pore structure model of combustible cartridge cases was established by virtue of the fractal geometry. Pore structure information, such as backbone fractal dimension and pore fractal dimension, of four kinds of combustible cartridge case were obtained by mercury intrusion porosimetry (MIP) . The formation mechanism of fractal pore structure of combustible cartridge was studied. The results show that the backbone fractal dimension consists of the component and influenced by the component number and size of components; the pore percolation fractal dimension reflects the pore structures of components; and the fractal dimension of pore structure is positively relative to the tensile strength of combustible cartridge case.

Direct hemoperfusion with a polymyxin B-immobilized cartridge in intestinal warm ischemia reperfusion

AIM： To investigate the effectiveness of direct hemoperfusion with polymyxin B-immobilized fibers （DHPPMX therapy） on warm ischemia-reperfusion （I/R） injury of the small intestine.METHODS： The proximal jejunum and distal ileum of mongrel dogs were resected. Warm ischemia was performed by clamping the superior mesenteric artery （SMA） and vein （SMV） for 2 h. Blood flow to the proximal small intestine was restored 1 h after reperfusion, and the distal small intestine was used as a stoma. The experiment was discontinued 6 h after reperfusion. The dogs were divided into two groups： the DHP-PMX group （n = 6, DHP-PMX was performed for 180 min; from 10 min prior to reperfusion to 170 rain after reperfusion） and the control group （n = 5）. The rate pressure product （RPP）, SMA blood flow, mucosal tissue blood flow, and intramucosal pH （pHi） were compared between the two groups. The serum interleukin （IL）-10 levels measured 170 min after reperfusion were also compared.RESULTS： The RPP at 6 h after reperfusion was significantly higher in the PMX group than in the control group （12174 ± 1832 mmHg/min vs 8929 ± 1797 mmHg/min, P 〈 0.05）. The recovery rates of the SMA blood flow at I and 6 h after reperfusion were significantly better in the PMX group than in the control group （61%±7% vs 44% ±4%, P 〈 0.05, and 59%±5% vs 35%±5%, P 〈 0.05, respectively）. The recovery rate of the mucosal tissue blood flow and the pHi levels at 6 h after reperfusion were significantly higher in the PMX group （61%±8% vs 31%±3%, P 〈 0.05 and 7.91±0.06 vs 7.69±0.08, P 〈 0.05, respectively）. In addition, the serum IL-IO levels just before DHP-PMX removal were significantly higher in the PMX group than in the control group （1 569 ± 253 pg/mL vs 211± 40 pg/mL, P 〈 0.05）.CONCLUSION： DHP-PMX therapy reduced warm I/R injury of the small intestine. IL-10 may play a role in inhibiting I/R injury during DHP-PMX therapy.

Strain concentration caused by the closed end contributes to cartridge case failure at the bottom

Ruptures at the bottom of cartridges are a common cause of failure of ammunitions,which directly threatens the safety of weapons and shooters.Based on plastic tube theory,this study analyses the radial and axial deformation of a cartridge,considering the radial constraint of the closed end at the bottom of the cartridge.Owing to the influence of the closed end,the bottom of a cartridge does not establish complete contact with the chamber.Owing to strain concentration in the non-contact area,this area is more amenable to the occurrence of cartridge rupture.This theory predicts the location of the fracture more accurately than the traditional theory.The maximum axial deformation of a cartridge comprises bending and friction deformation.The maximum strain at the bottom of the cartridge increased by 135%owing to the introduction of bending strain caused by the closed end.The strain distribution of a cartridge was measured using digital image correlation technology,and the measured result was consistent with the predicted results of the bending deformation theory and rupture case.The effects of wall thickness,radial clearance,friction coefficient,and axial clearance on the axial deformation of the cylinder were studied.Increasing the wall thickness and reducing radial clearance were found to reduce bending deformation;furthermore,lubrication and reduction in axial clearance reduce frictional deformation,which in turn reduce cartridge rupture.

Effect of hemoperfusion cartridge on different internal environmental indicators

BACKGROUND:This study aimed to observe the effect of hemoperfusion(HP) cartridge on different internal environment indicators at different time points in patients with acute blood poisoning and to find alternative indicators for the detection of blood poisoning.METHODS:The levels of internal environment indicators(blood pH,P_vCO_2,P_vCO_2,blood lactate,potassium,free calcium,bicarbonate,and blood glucose) before and after HP treatment were recorded for patients with acute poisoning at time points of 30 minutes and 120 minutes.After calculating the difference value 5,the statistical software was used to analyze the statistical difference of the influence caused by HP cartridge at two time points.According to the formula,adsorption rate%=(a-v)/a×100,the adsorption rate of each indicator was calculated respectively.RESULTS:The difference of indicators at different time points in inlet and outlet such as blood glucose,free-calcium,and lactate was statistically significant(P<0.05),but the difference in indicators such as pH,P_vCO_2,P_vO_2,potassium,sodium,and bicarbonate was not statistically significant(P>0.05).CONCLUSION:During HP treatment,the indicators of blood glucose,free-calcium and lactate were significantly affected by HP cartridge,and the effect varies with time.

Experiment and simulation of launching process of a small-diameter steel cartridge case

In order to explore the rules of the deformation force during the launching of a small-diameter steel cartridge, the semi-closed bomb test method is used to test the greatest strains on chamber outer wall under the different chamber pressures. The pressure curves of cartridge chamber are measured in experiment, and the tensile test data of cartridge are loaded into the numerical calculation to compare with the experimental data. The conclusion was obtained that the calculated results match better with the experimental results by considering strain rate bilinear kinematic hardening material constitutive model. The forces on the various parts of the cartridge during launching and their deformation rules are achieved, in which the equivalent plastic strain decreases and the cylinder ring withstands the maximum equivalent stress when the cartridge case clings to the bore from the mouth to the bottom.

Purification of Astaxanthin from Laminaria japonica by Ionic Liquid-based Monolithic Cartridge

An effective and accurate method was developed for the extraction of astaxanthin from Laminariajapo- nica with subsequent separation by ionic liquid-based monolithic cartridge. The optimized extraction conditions in- cluding extraction solvent（ethanol）, extraction time（90 min） and ultrasonic power（75 W） were obtained by systema- tical investigation. Chromatographic analysis was performed on a C18 column with ultraviolet（UV） detection at 476 nm, and a solution consisting of methanol/acetonitrile/H2O/dichloromethane（83：6：6：5, volume ratio） was used as the mobile phase at a flow rate of 0.7 mL/min. After ionic liquid-based monolithic solid phase extraction, 17.82 μg/g as- taxanthin was obtained from Laminaria japonica. This ionic liquid-based monolithic cartridge exhibits high affinity and selectivity for astaxanthin, and it can be potentially used as the stationary phase of high performance liquid chromatography（HPLC）.

An experimental and numerical approach-characterisation of power cartridge for water-jet application

Power Cartridges are pyrotechnic devices where hot combustion gases utilized to do mechanical work for disruption of suspected Improvised Explosive Devices(IEDs). It plays a vital role either in destroying the suspicious object or making them non-functional by generating the gas pressure on burning of propellant against the water column inside the barrel, Present work is focused on characterisation,numerical solution such as deformation; strain; stress using FEM(Finite Element Method), design qualification, performance and evaluation of power cartridge for disruptor application. Experimental trials for pressure-time(P-t) measurement in closed vessel(CV), various electrical parameters like all fire current(AFC), no fire current(NFC) and ignition delay have been measured. Further, mechanical properties for brass material have been determined. An attempt has been made to characterise the power cartridge by FEM and carrying out the experiments for water-jet application.

Effect of Methanol in the Wash-Solvent Bottle and the OnGuard Cartridges on the Determination of Different Anions Using Ion Chromatography

The effect of using methanol in the flush-solvent bottle of the auto-sampler of Ion Chromatograph on the determination of sulfate ions was studied using AS11-HC 2 mm analytical column. The use of 50% methanol in the flush solvent bottle results in overestimation of sulfate concentration by 18%. However, the use of 10% methanol instead of 50% did not show such error in the determination of sulfate using the same column. Furthermore, the effect of using OnGuard-RP and OnGuard-P cartridges for sample pretreatment on the determination of different anions was also studies using AS14-HC 2 mm analytical column. The results indicate that using OnGuard-RP cartridge caused the concentration of fluoride, bromide, nitrate, phosphate and sulfate ions to be underestimated, whereas the concentration of chloride ions to be overestimated. The error in the determination of fluoride, bromide, nitrate, phosphate sulfate, and chloride was found to be 40.0%, 26.0%, 22.8%, 26.8%, 18.0%, and 25.0% of the certified standard concentration, respectively. It was also found that the use of OnGuard-P cartridge resulted in underestimation of fluoride, chloride, bromide, nitrate, phosphate, and sulfate by 60.0%, 40.0%, 82.0%, 87.2%, 45.2%, and 39.0% of the certified standard concentration, respectively. These findings point out to careful corrections that should be considered in any application of ion chromatography utilizing such sample pretreatment.

Theoretical and numerical investigations on the headspace of cartridge cases considering axial deformation and movement

The cartridge case headspace is the axial clearance between the cartridge and bolt of an automatic weapon,and influences the reliability and security of the weapon.Accordingly,theoretical and numerical studies were conducted to analyze the dynamic response of cartridge cases during internal impact considering the initial radial clearances between the cartridge case and chamber.A theoretical model was proposed to predict the cartridge case headspace considering both the deformation and movement of the cartridge case and confirmed by the results of nonlinear finite element simulations.The differences between the results of the conventional static model and the dynamic model were then comprehensively evaluated.The effects of the angle between the cartridge and chamber,the cartridge case material,and the intermal impact pressure on the predicted headspace value were also analyzed.The dynamic response of the cartridge case predicted by the dynamic model was more accurate than that predicted by the conventional static model.The internal impact pressure,pressure change rate,and cartridge material were all found to affect the predicted headspace.

Analysis of Structural State of 60/40 Brass Cartridge Case (BCC) after Being Exposed to High Pressure and Temperature of Firing

This research presents an experimental and analytical study of the structural state of the 60/40 brass cartridge case, (BCC) after being fired. The oral section of the BCC has the function of confining the gases of firing by expanding against the chamber and sealing the gases. Firing conditions, namely, high pressure and temperature, 3000 bar and 2727&#176;C, respectively, affect performance properties of the (BCC). These are confining and crack strengths. Experimental study was done on the oral section to address these effects on the structural and mechanical properties of this brass. This alloy is a 60% copper (Cu) and 40% zinc (Zn) alloy and has a two-phase structure, alpha, (α) and beta, (β). Using “before and after” comparison approach;performance properties were tested in cartridge cases prepared before and after firing. These properties are hardness, tensile strength, micro-structural and chemical composition. Comparing the tests’ results, after firing demonstrated considerable degrading in performance properties, micro-structural disorder and a remarkable deficiency in the zinc element in the brass structure. This deficiency affects the percentage of beta phase in the alloy which governs the strength of the brass. According to the required properties before firing, it was found that after firing, the brass cartridge case is not qualified for reloading.

Research on rotary forming mechanism of cartridge bottom by FEM

The rotary forging of a cartridge bottom is simulated by finite element method with DEFORM TM . The analysis of stress and strain rate results indicates that the deformation conditions and the final geometry of a product are not completely axis symmetrical under the partial loading conditions during the rotary forging operations. It is therefore required to have a few more rotary forging cycles at the end of total feeding to eliminate nonuniformity. The results of simulation show that the optimization of rotary forging process conditions can be achieved to avoid the underfill defect resulting from improper process conditions. This technology can be used to manufacture ring components with thin bottoms by properly controlling the working process and the tooling motion.

Design of a 70 MPa Two-Way Proportional Cartridge Valve for Large-Size Hydraulic Forging Press

For an ultra-high-pressure hydraulic transmission system of a large-size hydraulic forging press(LHFP),a 70 MPa two-way proportional cartridge valve has been developed to improve the power weight ratio of the hydraulic forging press.In this study,a nominal diameter 25 mm(DN25)cartridge valve is taken as the research object.A longer concentric cylindrical annular gap is set to effectively prevent the ultra-high-pressure oil from flowing to the pilot stage and a seated valve structure is set to form the linear sealing zone in the closing state of the main valve port.Electric-displacement feedback is adopted to realize precise control of the main valve port flow and the features of this valve are investigated.In order to verify the strength and static and dynamic characteristics,the finite element model and a simulation model of the valve proposed above are built.There is a little deformation which does not affect the main valve spool movement,and the main valve port flow meets the design demands.Then,the prototype of DN2570 TPCV is manufactured and a ultra-high-pressure experimental platform is developed.The experimental results show that the DN2570 TPCV designed in this study has the advantage of fast response,high control precision,and low leakage,which can meet the requirements of LHFPs.

TANDEM REPEATING OF THE EXPRESSIONCARTRIDGE──A NOVEL STRATEGY TOENHANCE THE EXPRESSION EFFICIENCY OFCLONED GENE IN ESCHERICHIA COLI

A novel strategy to enhance the expression efficiency of cloned target gene in Escherichia coli was developed. The whole expression cartridge , consisting of promoter. SD sequence , target gene and transcription terminator, was tandem repeatedly engineered into a expression plasmid. Consequently, the copy number of specific gene was increased substantially, leading to the improvement of expression efficiency.Using this approach, a recombinant plasmid , designed as PLYD, was constructed and transformated into the Escherichia coli strain DH5α. Upon induction , the desired protein was synthesized in a considerable level and accumulated up to 63% of the total cell proteins. The present study revealed that tandem repeating of expression cartridge provided a convenient means to improve expression level efficiently.

Response of Different Varieties of Red Cartridge Kiwifruit to Temperature and Precipitation in Growth Stages

The responses of Hongyang,Donghong and Jinhong varieties to temperature and precipitation were analyzed by observing the growth stages of different kiwifruit varieties in Longhe red cartridge kiwifruit base of Liuzhi Special Zone of Guizhou Province in 2021 and combining with the meteorological data of temperature and precipitation in the base in the same period.The results showed that Hongyang,Donghong and Jinhong all sprouted on February 1,and had the same response to temperature and precipitation.From germination to leaf spreading stage,Hongyang and Donghong had the same response to precipitation,while Donghong and Jinhong had the same response to temperature,but Jinhong needed 32.5 mm precipitation to meet its growth and development.From leaf spreading stage to budding stage,Hongyang and Donghong had similar responses to temperature and precipitation,while Jinhong needed average daily temperature of 16.5℃and precipitation of 2.1 mm.The responses of the three varieties from budding to flowering to temperature and precipitation were consistent.From flowering to fruiting,Hongyang needed 19.9℃temperature and the least precipitation,while Jinhong needed the lowest temperature and the maximum precipitation.Donghong's response to temperature and precipitation was between Hongyang and Jinhong.During the period from fruit setting to fruit ripening and picking,Hongyang needed the least temperature and precipitation,while Donghong and Jinhong had the same response to temperature and precipitation.In the key period of fruit expansion of the three kiwifruit varieties in 2021,temperature and precipitation were the most suitable for fruit expansion.In short,red cartridge kiwifruit has a good response to temperature and precipitation in different growth stages,and it requires 201 d for Hongyang variety from germination to maturity and picking,211 d for Donghong variety and 218 d for Jinhong variety.

正负脉冲电压驱动的电磁螺纹插装阀动态特性分析

提出了一种基于PWM技术的正负脉冲电压控制策略,用于提高锥阀式电磁螺纹插装阀启闭动态响应速度,使其满足数字液压技术的要求。在分析电磁螺纹插装阀结构和工作原理基础上,建立了电磁螺纹插装阀的数学模型,并在AMESim软件中搭建电磁螺纹插装阀及其测试系统的多物理场耦合建模,研究不同正负脉冲电压持续时间条件下电磁螺纹插装阀线圈电流、阀芯位移、电磁力的变化规律,确定了电磁螺纹插装阀响应速度最快时正负脉冲电压控制策略的最优控制参数。利用半实物仿真系统搭建SCV硬件在环测试实验台,对所提正负脉冲控制策略进行验证。实验表明,与常规电压控制策略相比,当正负脉冲电压控制策略中正负脉冲电压持续时间都为10 ms时,电磁螺纹插装阀的开启时间由30 ms缩短到13.5 ms,其关闭时间由139 ms缩短到14 ms。研究结果为电磁螺纹插装阀的高响应化和数字液压技术的发展提供参考。

温度梯度对树脂锚固材料蠕变特性的影响

为探究深部巷道围岩锚固支护结构在高地温环境下的长期稳定性,以树脂锚固材料为例,利用单轴压缩试验、单轴蠕变试验以及蠕变修正模型,研究了树脂锚固材料在不同温度环境下的自身强度及蠕变特性。结果表明:温度对树脂锚固剂抗压强度的影响比较大,抗压强度随着温度的升高大致呈线性衰减,衰减速率约为0.48 MPa/℃;随着温度升高和应力水平的增加,树脂锚固剂的蠕变量和蠕变速率逐渐加快,蠕变破坏阈值减小;修正过后的广义开尔文蠕变模型不仅极大地克服了原蠕变模型在加载应力范围上的局限性,还可以很好地描述并且预测不同温度、不同应力水平下的树脂锚固剂的蠕变特性和变化趋势;SEM电镜扫描显示,温度越高,树脂锚固剂内部的裂缝就越明显。

高温高压高产气体封隔器卡瓦力学行为的分析与实验

为了提高海上“三高”气井管柱的安全性,确保卡瓦良好的工作性能,以HPC070401封隔器双向筒式卡瓦为例,将滑移线理论法、数值模拟和实验法相结合,研究卡瓦咬入过程的力学行为,分析卡瓦与套管的接触应力分布规律、卡瓦牙咬入套管的深度和疲劳寿命,建立了封隔器卡瓦系统工作可靠的充分必要准则。研究结果表明:坐卡压力增加,卡瓦牙咬入套管的深度也随之增加,在坐卡压力为35、42、48、55 MPa时,卡瓦咬入套管深度为0.25993、0.29425、0.32353、0.36561 mm;坐卡压力增加,卡瓦牙尖局部塑性变形增大,在坐卡压力35、42、48、55 MPa下,对称循环波动20%时,卡瓦疲劳循环次数为951110、789540、717160、629260;通过高温高压封隔器卡瓦锚定实验,卡瓦咬入套管的实测深度介于0.350~1 mm之间,与有限元模拟结果较吻合;结合评价准则和高温高压封隔器疲劳实验可知,套管因疲劳累积损伤产生的应力松驰系数为0.18。

盾构螺机后仓门液压系统仿真控制研究

针对传统盾构螺旋输送机后仓门紧急关闭过程中液压系统流量大小不稳定及油缸和蓄能器关键参数设置不合理而易引起液压冲击,造成机械部件损伤等缺陷。提出一种带压力补偿的插装式比例流量阀控制系统流量大小。通过分析其结构组成及原理,建立了该阀AMEsim模型,并对模型仿真特性曲线进行了分析,得出其有较好的流量稳定性,控制精度高、动态响应性好,且利用仿真环境建立了螺机后仓门液压系统的AMEsim模型,分析了系统中蓄能器与液压缸的关键参数对后仓门紧急关闭的影响规律,结合该影响规律及比例流量阀的工作特性,为螺机后仓门液压系统的进一步升级改造提供理论依据。