Defence Science Journal最新文献_第6页

Experimental study on dynamic mechanical properties of projectile 155mm ERFB BT material 弹丸用155mm ERFB BT材料动态力学性能试验研究

4区工程技术

Defence Science Journal Pub Date : 2023-05-12 DOI: 10.14429/dsj.73.18644

Rajesh B. Ohol, Tekram N. Parshuramkar, B. A. Parate, Dineshsingh G. Thakur

{"title":"Experimental study on dynamic mechanical properties of projectile 155mm ERFB BT material","authors":"Rajesh B. Ohol, Tekram N. Parshuramkar, B. A. Parate, Dineshsingh G. Thakur","doi":"10.14429/dsj.73.18644","DOIUrl":"https://doi.org/10.14429/dsj.73.18644","url":null,"abstract":"Artillery projectile 155mm high explosive (HE) extended range full bore boat tail (ERFB BT) and its components experience a high pressure loading of the propellant during gun launch. Mechanical properties of an engineering material are measured using quasi-static tensile test at room temperature. The materials of the projectile and its components are expected to survive time dependent propellant pressure loading inside the gun, which lasts for few microseconds. To investigate dynamic mechanical properties of the projectile and its components at medium strain rates and elevated temperature, the experimental analysis is undertaken. This research paper aims to examine the effect of medium strain rates and elevated temperatures on flow properties of the materials used in the projectile. The uniaxial tensile tests at the medium strain rates between 0.01 s-1 to 1s-1 and at elevated temperatures ranging between 150°C to 500°C are performed separately. The Considѐre criterion was applied to evaluate strain hardening exponent of the materials. Values of strain hardening exponents of shell body and boat tail materials are less than that of driving band material. Strain rate sensitivity of the materials is observed to be very low, thus indicating a good resistance to plastic deformation. The yield strength and true yield strength of the materials fall with increase in temperature. ","PeriodicalId":11043,"journal":{"name":"Defence Science Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135421703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Aero structural and Electromagnetic Design Optimisation of Maritime Patrol Aircraft Radome Using Direct Search Algorithms 基于直接搜索算法的海上巡逻机天线罩气动结构和电磁设计优化

4区工程技术

Defence Science Journal Pub Date : 2023-04-18 DOI: 10.14429/dsj.73.17889

M.R. Shankar, A.C. Niranjanappa, B. Dattaguru

引用次数: 0

A Novel Scheme of an Optimal Data Rate Transmission for Airborne Telemetry of Long Range Aerospace Vehicle 一种远程航天飞行器机载遥测最优数据速率传输新方案

IF 0.9 4区工程技术

Defence Science Journal Pub Date : 2023-03-13 DOI: 10.14429/dsj.73.17355

Sudarsana Reddy Karnati, Lakshmi Boppanna, D. R. Jahagirdar

引用次数: 0

Machining and Tribological Characterisation of Uncoated and Coated Carbide Inserts while Turning Tungsten Heavy Alloy 车削钨重合金时未涂层和涂层硬质合金刀片的加工和摩擦学特性

IF 0.9 4区工程技术

Defence Science Journal Pub Date : 2023-03-13 DOI: 10.14429/dsj.73.17853

S. S, A. Priyadarshini, P. Chaganti, G. Prabhu

{"title":"Machining and Tribological Characterisation of Uncoated and Coated Carbide Inserts while Turning Tungsten Heavy Alloy","authors":"S. S, A. Priyadarshini, P. Chaganti, G. Prabhu","doi":"10.14429/dsj.73.17853","DOIUrl":"https://doi.org/10.14429/dsj.73.17853","url":null,"abstract":"Tungsten heavy alloys are high density alloys containing 80 to 98 wt.% tungsten and the balance is a matrix made of relatively low melting elements such as copper, nickel and iron. These alloys are used as radiation shields, CG adjusters and also in armour piercing ammunition. Machining these alloys to close tolerances and finish leads to excessive tool wear, surface damage and hence proves to be a challenging task. This study focuses on turning operation carried out under dry and wet cutting conditions using three different commercially available cemented carbide inserts. Three different feed rates have been used at a constant depth of cut and cutting speed. The best possible cemented carbide tooling solution for machining tungsten heavy alloys has been determined based on the surface finish obtained, chip geometry, cutting forces, and machining temperature. The observations made during machining are correlated to the tribological behavior of the inserts and the alloy with the help of pin-on disc tests. Coated cemented carbide inserts provide surface roughness values lower than 1 µm under finish turning conditions. On the other hand, PVD coated inserts give consistently better results over different feed rates and are found to experience lower tool wear for the specific cutting conditions. Analytical tool wear model suggests better tool life for the PVD coated insert.","PeriodicalId":11043,"journal":{"name":"Defence Science Journal","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44436011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Simulation and Analysis of Electro Mechanical Actuator with Position Control 带位置控制的机电作动器仿真与分析

IF 0.9 4区工程技术

Defence Science Journal Pub Date : 2023-03-13 DOI: 10.14429/dsj.73.18284

Rengasamy S, M. D., R. R

{"title":"Simulation and Analysis of Electro Mechanical Actuator with Position Control","authors":"Rengasamy S, M. D., R. R","doi":"10.14429/dsj.73.18284","DOIUrl":"https://doi.org/10.14429/dsj.73.18284","url":null,"abstract":"In recent times, Electro-Mechanical Actuator (EMA) is widely employed in various aerospace applications \u0000because of its compactness, ease of maintenance, and cost efficiency. It attracts most of the researcher for simulation and performance analysis. It is very much important to study its control system behaviour. In general, EMA requires, three loop cascade control, but for aerospace application two loop cascade control is used for speed and position controls due to dynamic load changing requirement. Most research efforts on EMA system has used a transfer function model of all its subsystems. Nevertheless, this technique does not yield complete outcomes for analysing its performance. To analyse its performance and characteristics in dynamic condition, an experimental model is essential. In addition, this model needs to cater for analysing performance of different capacity EMA. The primary goal of this work is to simulate unique EMA model with position control using a practical data and analyse its performance. In this design, EMA is modelled by three-phase Brushless Direct Current (BLDC) motor, six-step commutation logic, a speed sensor (Tacho) and a position sensor using Linear Variable Differential Transformer (LVDT). Position and speed controls are handled by Proportional (P) and Proportional plus Integral (PI) controllers respectively. The process reaction curve method is used to tune the controllers. This tuning approach is adequate to enable accurate and robust speed and position control. This paper focus on the simulation and performance analysis of a practical EMA system with position and speed controls in matlab-simulink. The performance analysis results shows that simulated model characteristic is close to physical system and reliable.","PeriodicalId":11043,"journal":{"name":"Defence Science Journal","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49016698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Design and Performance Analysis of a Switched Reluctance Motor Using Finite Element Analysis and Magnetic Equivalent Circuit Model 基于有限元分析和磁等效电路模型的开关磁阻电机设计与性能分析

IF 0.9 4区工程技术

Defence Science Journal Pub Date : 2023-03-13 DOI: 10.14429/dsj.73.17828

Sandesh Bhaktha B., Satish Kumawat, J. Pitchaimani, Gangadharan KV

{"title":"Design and Performance Analysis of a Switched Reluctance Motor Using Finite Element Analysis and Magnetic Equivalent Circuit Model","authors":"Sandesh Bhaktha B., Satish Kumawat, J. Pitchaimani, Gangadharan KV","doi":"10.14429/dsj.73.17828","DOIUrl":"https://doi.org/10.14429/dsj.73.17828","url":null,"abstract":"By being magnet-free, and mechanically robust with a longer constant power range, switched reluctance motor (SRM) is gathering much attention as a potential choice to propel electric vehicles (EVs) and hybrid electric vehicles (HEVs). This paper comprehensively investigates the performance sensitivity to geometric design variables such as rotor diameter, pole arc angles, and yoke thicknesses for an SRM using static two-dimensional (2D) electromagnetic Finite-Element Analysis (FEA). The reason for the change in static characteristics due to variation in reluctance between SRM designs has not been detailed previously. This is addressed by the magnetic equivalent circuit (MEC) model that simplifies the design analysis. Results indicate that stator pole reluctance needs to be given due importance while studying the influence of rotor diameter. Also, it is imperative to set an adequate thickness of the stator and rotor yokes to minimize the effect of saturation on the performance. Rotor diameter and stator pole arc angle have a pronounced influence on the performance while the influence of rotor pole arc angle and yoke thicknesses was relatively less.","PeriodicalId":11043,"journal":{"name":"Defence Science Journal","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46275211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigation of the Mechanical Properties of the Barrel After Geometric Changes on the Mortar 砂浆几何变化后筒体力学性能的研究

IF 0.9 4区工程技术

Defence Science Journal Pub Date : 2023-03-13 DOI: 10.14429/dsj.73.18087

H. Pihtili, M. Ulutaş

{"title":"Investigation of the Mechanical Properties of the Barrel After Geometric Changes on the Mortar","authors":"H. Pihtili, M. Ulutaş","doi":"10.14429/dsj.73.18087","DOIUrl":"https://doi.org/10.14429/dsj.73.18087","url":null,"abstract":"The area close to the firing part as of the muzzle of a 120 mm mortar consists of trapezoidal threads. In order for the 120 mm mortar to hit the target, the target is aimed by giving the required angle with the help of these trapezoidal screw threads. Since it takes a lot of time to set the target in this way, the aim is to develop a hydraulic mechanism that automatically gives an angle to the system by lifting the trapezoidal screw threads instead of mechanically setting the angle to be adjusted easily in the shortest time. Thus, it is intended to convert the mortar into a full-automatic system that can rotate 360° around itself and can be adjusted to the desired angle in a short time and very precisely. The present study is conducted in two steps. At first, thermo-mechanical analyzes for the stresses affecting during firing of the currently used 120 mm mortar with a screw thread were investigated by ANSYS Workbench finite elements method. Then, the status of the mortar after removing the screw threads was examined in the ANSYS Workbench program under the effect of the same stresses and the results were compared between the two mortars and it was examined whether it is safe to remove the screw threads.","PeriodicalId":11043,"journal":{"name":"Defence Science Journal","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48718205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An Architecture for On board Frequency Domain Analysis of Launch Vehicle Vibration Signals 运载火箭振动信号的车载频域分析体系结构

IF 0.9 4区工程技术

Defence Science Journal Pub Date : 2023-03-13 DOI: 10.14429/dsj.73.17690

R. Srinivasan, B. Lakshmi, Tessy Thomas

{"title":"An Architecture for On board Frequency Domain Analysis of Launch Vehicle Vibration Signals","authors":"R. Srinivasan, B. Lakshmi, Tessy Thomas","doi":"10.14429/dsj.73.17690","DOIUrl":"https://doi.org/10.14429/dsj.73.17690","url":null,"abstract":"The dynamic properties of the airborne structures plays a crucial role in the stability of the vehicle during \u0000flight. Modal and spectral behaviour of the structures are simulated and analysed. Ground tests are carried out with environmental conditions close to the flight conditions, with some assumptions. Subsequently, based on the flight telemetered data, the on-board mission algorithm and the auto-pilot filter coefficients are fine tuned. An attempt is made in this paper to design a novel architecture for analysing the modal and spectral random vibration signals on-board the flight vehicle and to identify the dominant frequencies. Based on the analysed results, the mission mode algorithm and the filter coefficients can be fine tuned on-board for better effectiveness in control and providing more stability. Three types of windows viz. Hann, Hamming and Blackman-Harris are configured with a generalised equation using FIR filter structure. The overlapping of the input signal data for better inclusiveness of the real-time data is implemented with BRAM. The domain conversion of the data from time domain to frequency domain is carried out with FFT using Radix-2 BF architecture. The FFT output data are processed for calculating the power spectral density. The dominant frequency is identified using the array search method and Goldschmidt algorithm is utilised for the averaging of the PSDs for better precision. The proposed architecture is synthesised, implemented and tested with both Synthetic and doppler signal of 300 Hz spot frequency padded with Gaussian white noise. The results are highly satisfactory in identifying the spot frequency and generating the PSD array.","PeriodicalId":11043,"journal":{"name":"Defence Science Journal","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46118620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Monopole Cavity Resonator Antenna with AMC and Superstrate for 5G WiMAX Applications 5G WiMAX应用中具有AMC和超高速率的单极腔谐振天线

IF 0.9 4区工程技术

Defence Science Journal Pub Date : 2023-03-13 DOI: 10.14429/dsj.73.17759

A. Verma, R. Arya, Srinivasa Nallanthighal Raghava

{"title":"Monopole Cavity Resonator Antenna with AMC and Superstrate for 5G WiMAX Applications","authors":"A. Verma, R. Arya, Srinivasa Nallanthighal Raghava","doi":"10.14429/dsj.73.17759","DOIUrl":"https://doi.org/10.14429/dsj.73.17759","url":null,"abstract":"For 5G and WiMAX applications, a coplanar waveguide (CPW)-fed monopole antenna sandwiched between an artificial magnetic conductor (AMC) and a superstrate is investigated. Because traditional planar antennas have low gains, they are unsuitable for a wide range of applications. This paper explores scientific strategies for increasing radiation gain in low-gain antennas such as planar monopoles. We use AMC in conjunction with superstrate to achieve a high gain antenna, with the monopole antenna serving as the primary radiator. However, a superstate like this demands the use of materials with high permittivity, and most of such materials are not readily available on the market. Even if such materials are available, they are mostly expensive and unsuitable for commercial systems. We investigate various superstrates and elaborate on which way these superstrates can be used interchangeably without compromising antenna performance. In the end, we fabricate one of these three superstrates. The antenna, which also employs AMC in tandem with the superstrate, has an impedance bandwidth ranging from 3.2 GHz to 3.75 GHz with 7 dBi gain, so it can be a viable candidate for 5G and WiMAX applications","PeriodicalId":11043,"journal":{"name":"Defence Science Journal","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42457395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Human and Environmental Bias Affecting Risk Perception in Military Radiological and Nuclear Operations 影响军事放射和核行动风险感知的人类和环境偏见

IF 0.9 4区工程技术

Defence Science Journal Pub Date : 2023-03-13 DOI: 10.14429/dsj.73.18212

E. Andrade, I. S. Alves, R. Stenders, A. L. Q. Reis

{"title":"Human and Environmental Bias Affecting Risk Perception in Military Radiological and Nuclear Operations","authors":"E. Andrade, I. S. Alves, R. Stenders, A. L. Q. Reis","doi":"10.14429/dsj.73.18212","DOIUrl":"https://doi.org/10.14429/dsj.73.18212","url":null,"abstract":"The urban military operating environment may offer favorable conditions for combat involving asymmetric actions or 4th generation warfare which includes the chemical, biological, radiological, or nuclear (CBRN) environment. The CBRN environment is characterized by threats and hazards capable of producing negative impacts to the operations. The detriment may be produced by intentional release of hazardous materials into the operational environment. This study deals with an environment deliberately contaminated by radioactive materials because of the activation of a radiological dispersive device (RDD). A computer simulation of the radioactive scenario was performed in order to produce useful information which in turn can be used to support decision-making. The main goal was to assess the risk of developing radio-induced solid cancer by studying the articulation between local environmental variables and a cognitive bias, the Dunning-Kruger effect. The findings highlight intuitive correlations between local atmospheric stability and cognitive bias affecting the threat level (radiation dose), the responsiveness and the perceived risk. The findings also allow us to infer that, especially in the military-operational context, the methodology proposed for the assessment of environment-human interactions may be decisive for correctly direct available resources, both human and material, reducing operational risk.","PeriodicalId":11043,"journal":{"name":"Defence Science Journal","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46496023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0