排序方式: 共有45条查询结果,搜索用时 15 毫秒
41.
差压式管道内检测机器人启动过程模拟仿真 总被引:2,自引:0,他引:2
基于CFD软件Fluent提供的计算方法,利用动网格技术和UDF(用户自定义函数),对差压式管道内检测机器人启动过程进行了动态模拟.该方法克服了以往静态研究的不足,更直观地反映了不同因素影响下机器人的启动情况.仿真结果表明:管内流体速度、机器人质量、管壁摩擦力、不同流体对机器人的启动过程都有明显影响.可为下一步研究机器... 相似文献
42.
《防务技术》2020,16(2):460-469
Machine gun barrels differ from their rifle counterparts in terms of profile. To support high rates of sustained fire, machine gun barrels are made thicker in order to dissipate more heat and maintain their flexural rigidity and thus accuracy, but on other hand they also contribute in weight addition to weapon. This investigation deals with comparison between a conventional machine gun barrel and an improved innovative design having T-fins, both having same weight and chambered in 5.56 × 45 NATO ammunition, to compare their structural and harmonic characteristics which were parameterized by factors such as modal spectrum, directional deformation at muzzle ends during a single shot fire and harmonic behaviour at corresponding range of exciting frequencies. The solid models of both the barrels having same weight, were created using Solidworks. The continuous input data functions were generated by MATLAB using the field tested discreet data points. The generated velocity-distance functions were converted into time dependent functions using integration algorithms to calculate transient parameters such as time steps, excitation frequency range, angle of rotation of projectile and its angular velocity. The dynamic condition simulated the varying nature of forces due to eccentricity in projectile and this data was fed to a time step study using ANSYS transient structural work bench followed by modal and harmonic analysis. The results showed a significant reduction in muzzle end deformation which thus proved that the T-finned barrel, although had same weight as that of the conventional one, but had better structural and harmonic characteristics, and hence it would inherit better firing accuracy. 相似文献
43.
螺栓法兰连接广泛用于各种工业结构中,为准确预测该连接在实际工作中发挥的作用,需要建立准确高效的有限元模型。针对有限元建模过程中模型各种参数的确定问题,综合使用数值仿真手段和试验手段分别对模型网格参数和接触参数的确定开展研究。参数确定后的螺栓法兰连接结构有限元模型在保证计算精度的前提下,计算效率得到显著提高。 相似文献
44.
45.
《防务技术》2020,16(6):1160-1166
Aluminium composites are inevitable in the manufacture of aircraft structural elements owing to less weight, superior corrosion resistance and higher specific properties. These composites reduce the weight of the aircraft, improve the fuel efficiency and enhance the maintenance duration. This study proposes the development of dissimilar grade aluminium (aluminium 1100-aluminium 5052) composites with different reinforcement’s viz., stainless steel wire-mesh, silicon carbide (SiC) powders and SiC powder interspersed wire-mesh, by explosive cladding technique. Wire-mesh enhances the friction and restricts the movement of flyer plate to craft a defect free clad, while SiC particles form a band on the interface. Highest strength is obtained when SiC powder interspersed wire mesh is employed as reinforcement. The dissimilar aluminium explosive clad with SiC particle reinforcement results in lower strength, which is higher than that of the weaker parent alloy and that of the conventional dissimilar aluminium explosive clads without any reinforcement. 相似文献