Effects of spinning on residual velocity of ogive-nosed projectile undergoing ordnance velocity impact

In the present article, finite element analysis (FEA) based simulation on the study of the impact of projectiles having ogive nose shape has been made using ANSYS explicit dynamics. The effects of spinning on the residual velocity of ogive nosed projectile undergoing ordnance velocity impact have been presented. The variations of residual velocity due to different projectile materials and target plate thickness have been evaluated when the projectile is impacted by translational and spinning velocity. The target plates and ogive nosed projectile of a given material are discretized, and a rigorous error and convergence study has been made. Subsequently, the residual velocity of the considered model is evaluated by numerical techniques based on FEA. The results with the optimized meshed model are compared with the analytical results using the penetration theory and found that the results are well compared. Parametric study of the residual velocity has been made with varied ogive nosed materials and target plate thickness when the ogive nosed projectile undergoing ordnance velocity impact. Based on the numerical results, it has been found that the ogive nose projectile having tungsten alloy material is more effective undergoing ordnance velocity impact compared to steel 4340 material. For a given target plate thickness, spinning velocity, and impact velocity, the residual velocity is about 3 percent higher for the projectile made up of tungsten alloy compared to the steel 4340. The effects of the target plate thickness on the residual velocity of the ogive nose projectile do not seem to have much significant effects. It may be due to the simple reason that the ratio of the target plate thickness to projectile diameter is remaining within the intermediate range, i.e. within 1 and 10.

Ferrocement Panels under High Velocity Impact by Incorporating Waste Foundry Sand

Ferrocement is widely used because of its excellent behavior pf ferrocement under flexural, and impact strength. Ferrocement also has excellent mechanical properties. In this study, total 16 ferrocement panels were modelled of M50 grade of concrete. The thickness of ferrocement panels considered is 15mm, 20mm and 25mm. Galvanized welded mesh is used as reinforcement in panels. This wire-meshes were layered in 2, 3, 4 and 5 layers. High velocity impact test is done by Ak-47 bullet striking with a velocity of 150, 250, 350, 450, 550, 650 and 750 m/s for each panel. All this panels were modelled in design modeler of Ansys explicit Dynamics. Deformation, Equivalent Stress and Normal Stress of all the panels are evaluated and compared by analyzing in ANSYS Explicit Dynamics. From the past researches and the conclusions made by these researches, we can see positive chance in the utilization of waste foundry sand in construction field. As these results gives the great emphasis towards the development on environment friendly and economical constructions.

An improvement design of groove-wound clothing on the licker-in—Part I. Theoretical analysis and modeling validation

This paper argues that the groove-wound licker-in racks’ spiral mounting leads teeth with an inclination angle to the rotating direction. Theoretical analysis of forces on the fibers is carried out when the inclination angle is 0 and θ: when the teeth enter the fiber layer, the inclination angle makes the pressure on fibers increases rapidly and leads to a stronger friction force on fibers. It also leads to increases in both contact area and the wrap angle of the fiber around the teeth. This article also uses ANSYS Explicit Dynamics to simulate the fiber assembly carded by a tooth, when the inclination angle is 0°, 1° and 2°. When the inclination angle of the model is 1°, its fiber deformation is 1.35 times that of 0°; its elastic strain and stress concentration coefficient are 1.40 times than that of 0°; when the inclination angle of the model is 2°, its fiber deformation is 1.72 times than that of 0°; its elastic strain and stress concentration coefficient are 2 times than that of 0°. As with the inclinations increasing, the fiber deformations increase in time grow from 0.0634 and 0.08477 to 0.10584. The simulation also shows that when the tooth works on the fibers, there is a sudden compressive stress on fibers and then this pressure transfers with time. From all of the above, the inclination angle on licker-in teeth results in larger strain and deformation on fibers, so that this inclination angle should be decreased as much as possible in practice.

An improvement design of groove-wound clothing on the licker-in—Part II. Application on the card machine

Due to spiral winding, there is an inclination angle between the teeth and the direction of the tangential velocity of the licker-in, which makes the teeth obliquely work with the fibers instead of vertically. In the previous work in Part I, we discussed the impacts of this using theoretical mechanical analysis and a digital model in ANSYS Explicit Dynamics. Based on the analysis, this paper makes a new type of card clothing for the licker-in and manufactures the rack by adding a process in the processing for traditional AT5610 × 05611 racks. The comparison of the two slivers worked by the traditional and new design licker-in card clothing show that the new design clothing has an increase of 24.41% on nep removal, which is consistent with the theoretical analysis. According to the paired samples test, the trash removal ratio and the short fiber content in the sliver, this new design shows no deterioration. For further discussion, we collect the noils and calculate the producing rate of the sliver, licker-in droppings and card strips with special collecting equipment. This new design shows a significant increase in the fiber yield percentage (8.45%) and a dramatic decrease for licker-in droppings (33.6%). Yarns from the new rack have better performance on breaking elongation (a decrease of 5.6%) and evenness. Therefore, this design has higher utilization for fibers and good commercial benefit.

Explosion Testing of a Polycarbonate Safe Haven Wall

The MINER Act of 2006 was enacted by MSHA following the major mining accidents and required every underground coal mine to install refuge areas to help prevent future fatalities of trapped miners in the event of a disaster where the miners cannot escape. A polycarbonate safe haven wall for use in underground coal mines as component of a complete system was designed and modeled using finite element modeling in ANSYS Explicit Dynamics to withstand the MSHA required 15 psi (103.4 kPa) blast loading spanning 200 milliseconds. The successful design was constructed at a uniform height in both half-width scale and quarter-width scale in the University of Kentucky Explosives Research Team’s (UKERT) explosives driven shock tube for verification of the models. The constructed polycarbonate walls were tested multiple times to determine the walls resistance to pressures generated by an explosion. The results for each test were analyzed and averaged to create one pressure versus time waveform which was then imported into ANSYS Explicit Dynamics and modeled to compare results to that which was measured during testing for model validation. This paper summarizes the results.

Study of Process Parameters on Machining Process Using Single Point Cutting Tool

This research work studies the influence of cutting process parameters used in single point cutting tool based machining operations. In this study design of experiment methodology is used for some qualitative outcome. Taguchi method is used for experiment design. It is solved using ANSYS Explicit Dynamics software. ANOVA analysis is also performed in this study using Minitab software. Results show that most critical factor which affects stress generated during cutting operations are rake angle of tool and feed rate. In this study model equations are also generated for further analysis using linear regression modelling technique using Minitab software.

Finite Element Analysis of Various Projectiles Modeled as Bullets

The objective of this research work was to perform a flow simulation around a running bullet and then compare and analyze three types of widely used bullet models. These are 7.62mm × 39mm, 7.62mm × 51mm, and 5.56mm × 45mm caliber popular NATO rounds respectively. Due to limited processing and computational resources, these bullet are modeled as cylindrical projectiles of similar length and diameter. Finite element analysis (FEA) are performed on these models using ANSYS explicit dynamics analysis code to investigate the effect of high velocity impact of these projectiles on a concrete plate. Three different types of meshing (coarse, fine, and fine with curvature) for each of these three cases have been used. Each projectile was fired at a different velocity. These velocities are selected in consultation with Hornady Manufacturing, Inc which has done extensive research on these bullets. The selected firing velocities for 7.62mm × 39mm, 7.62mm × 51mm, and 5.56mm × 45mm caliber bullets are 2021ft/s, 2539.4ft/s 2706.7ft/s respectively. Overall, the simulation result of explicit dynamics clearly demonstrated cavitation and mushrooming of projectiles when impacting a 0.25 inch concrete plate. The 5.56mm × 45mm projectile seemed to have the largest overall total deformation values of 2.0303, 1.0487, and 0.26079 feet as obtained from simulation of the three types of mashing. This can be attributed due to the higher velocity (2706.7ft/sec) as compared to the other two cases. Similarly, the 7.63mm × 39mm has the highest average change of velocity of 144.7, 92.3, and 99.6ft/sec respectively from the three types of meshing among the three bullets which can be attributed due to its lowest impact velocity (2021ft/s).