Papers by Keyword: Depth of Penetration

Abstract: Concrete is a widely used material for construction, playing a crucial role in infrastructural design. Recently, with the increase in threats and protection requirements, developments and investigations are continually needed in concrete for impact-resistant applications. This study investigates the ballistic performance of sixteen concrete formulations subjected to high-velocity impact using a 12.7×99 mm armour-piercing projectile fired from a single-stage gas gun at an impact velocity of 850 m/s. The experimental campaign evaluated depth of penetration (DOP), mass loss, and failure across different concrete formulations under the same test conditions. Concrete types included ordinary concrete (OC), steel- and basalt-fibre-reinforced mixes, ultra-high-performance concrete (UHPC), basalt fibre reinforced concrete (BFRC), rubber aggregate concretes (RSC), and cement-modified variants. Qualitative analysis, high-speed camera sequences, and three-dimensional (3D) scanning were employed to assess the penetration response of each configuration. Results show that UHPC formulations exhibited the best ballistic resistance, with DOP values reduced by nearly 50% compared to ordinary concrete. Steel-fibre-reinforced concretes showed a fibre-dosage-dependent improvement in DOP and material retention, with SF160 emerging as the most balanced solution. In contrast, rubber-modified mixes demonstrated higher DOP but effectively limited surface scabbing. These findings highlight the importance of material composition in optimising ballistic performance and guide the selection of concrete systems for infrastructure protection applications.

Abstract: Adhesive sandwich structures with the honeycomb core of the metallic foil, polymeric papers and composites are widely and effectively used in the units of aerospace engineering and in the other industries owing to a number of undeniable advantages, including high specific strength and stiffness. In the process of designing and manufacturing of abovementioned structures, it is necessary to ensure high strength and reliability of the adhesive joint of the bearing skins and honeycomb core at a small area of their contact. The decisive factors influencing the bearing capacity of such joint are the technological parameters of the bonding process. Using the finite element modeling, the paper deals with the bearing capacity of the adhesive joint of bearing skins with the honeycomb core based on the aluminium foil and polymeric paper Nomex at transversal tearing for the key factors of the bonding process. The pattern of the adhesive joint failure (on the adhesive of honeycombs) has been revealed, depending on the depth of penetration of honeycombs ends in the adhesive, physical and mechanical characteristics of honeycombs, modulus of elasticity and tearing strength of the adhesive and thickness of the adhesive layer. Peculiar features of behavior of adhesive joints of the bearing skins with the honeycomb core based on the aluminium foil and polymeric paper Nomex under the load have been established, which should be taken into account in designing and manufacturing of honeycomb structures. The recommendations are given with regard to choosing of parameters of the process of honeycomb structure bonding, which allow providing with the acceptable accuracy the optimal depth of penetration of ends of the honeycomb core faces in the adhesive layer of specified depth.

Abstract: This study evaluates the effect of process parameters on depth of penetration and surface roughness in abrasive waterjet (AWJ) cutting of copper. Full factorial experiments are carried out on trapezoidal blocks for each of the three abrasive particle sizes used. Experimental parameters - abrasive mass flow rate, water jet pressure and traverse speed are varied at three levels. Main effects and contributions of process parameters to depth of penetration and surface roughness is calculated. From the data, it is observed that, high abrasive mass flow rate, high water jet pressure and low traverse speed resulted in higher depth of penetration and a high abrasive mass flow rate, high water jet pressure and low traverse speed resulted in lesser R_a value. Using experimental data a statistical model for predicting depth of penetration & surface roughness is developed. Error between experimental and statistical values are compared to validate the statistical model. The maximum DOP of 49.32mm was observed at AMFR=405.4 g/min, P=300 MPa, TS=60 mm/min, MS=60 Mesh and minimum DOP of 4.27mm was observed at AMFR=200 g/min, P=100 MPa, TS=90 mm/min, MS=80 Mesh.

Abstract: The penetration characteristics of EBW are primarily dependent on the main beam current (Iw), potential difference between the cathode and anode (voltage, V) and the welding speed (S). There are other influencing parameters like weld focus current (If), welding gun to work distance (GW) and beam oscillation.In the present study, the effect of work distance on focus current and on penetration of Ti6Al4V weld is studied using a 60kV, 30kW EB welding machine. Weld focus current is measured over a range of work distance and variation in its pattern is studied. Similarly, the variation of depth of penetration by varying the work distance and varying the focus current at a particular work distance constant are also analyzed.It is observed that, focus current is inversely proportional to the work distance and the variation in focus current per unit change of work distance is high in the shorter work distance region. The change in focus current and work distance affects the weld penetration and fusion zone geometry. For optimum penetration at a given work distance, the beam focus should be below the surface in keyhole welding. As the work distance increases, the penetration capacity of the beam decreases and maximum penetration is obtained in lesser work distance region.

Abstract: The effect of the obliquity of a long-rod penetrator on the depth of penetration (DOP) into a witness block has been investigated by NET3D code based on a 3D finite element model with SK constitutive model and polynomial equation of state. The calculation results herein are in general agreement with limited number of experimental data and are very close to the calculation results of the CTH code, both of which are available in the literature. By combining with the present results with existing data, the DOP turns out to decrease rapidly with obliquity up to 30^o, decrease relatively slowly up to 70^o, and show a saturation behavior thereafter up to 90^o.

Abstract: Abrasive waterjet (AWJ) turning is an emerging technology, which plays an important role in machining cylindrical parts with the distinct advantages of negligible thermal effects and extremely low cutting force. This paper presents an experimental study of abrasive waterjet turning (AWJT) of Al₂O₃ ceramics. The machining process and performance in terms of the depth of penetration (DOP), surface roughness (Ra) and actual impact angle (β) are discussed to understand the effect of standoff distance (SOD) on the processing performance at two different turning modes. Based on the results of these investigations, there is a significant change of DOP and Ra at different SOD in radial mode turning and the optimal SOD of gaining maximum DOP and the minimum Ra is about 5.5mm.However, the DOP is nearly independent on the SOD in offset mode turning. Smaller Ra and DOP can be obtained in offset mode. Furthermore, the results indicate that the roundness error of cylinder parts is probably improved with the proper SOD interval in radial mode turning and it is suitable for machining cylinder part with considerably different radial size. The offset mode turning as the next operation after radial mode turning is recommended to process workpiece with excellent roundness. In this way, by understanding the effect of SOD on processing alumina ceramics, the paper establishes a good basis for developing strategies for optimizing processing parameters in order to generate the desired part geometry and achieve better surface quality.

Abstract: For uneven temperature distribution of infrared hot recycling of asphalt mixtures, principle and advantage of microwave hot recycling are introduced. Maxwell's equations are applied to build electromagnetic transmission model of recycled asphalt mixtures. Considering asphalt mixtures as dielectric substance, reflection and refraction of electromagnetic field are researched and model of standing wave ratio is built. Equation of magnetic attenuation is applied to contrast attenuation depths of different pavement materials. The results lay a good theoretical foundation to improve heating efficiency and choose pavement materials.

Abstract: In Gas Metal Arc Welding (GMAW) process, one of the main goals is to reach high depth of penetration as a characteristic of quality. This requires high amount of input heat. On the other hand high amount of input heat causes the increase in dimensions of heat affected zone (HAZ) which is not desirable. In this paper, an objective function including both depth of penetration of weld bead and the width of heat affected zone namely F = (HAZ+t) / (P+t) has been considered where, HAZ, P, and t denote the width of heat affected zone, the depth of penetration, and thickness of test pieces respectively. A five level five factor rotatable central composite design was used to collect the data for depth of penetration and width of heat affected zone. After collecting the data, the regression equation of objective function was obtained as a function of wire feed rate, welding voltage, nozzle-to-plate distance, welding speed and gas flow rate using least squares method. Then the objective function (f) was minimized by using the Imperialist Competitive Algorithm. One can be sure that the width of HAZ will decrease and the depth of penetration will increase due to minimization of the objective function. The computational result demonstrates that the proposed optimization algorithm is quiet effective in minimizing the objective function. The result shows that in order to obtain higher depth of penetration and lower width of heat affected zone at the same time, wire feed rate, arc voltage and nozzle-to-plate distance must be at their lowest levels while welding speed and gas flow rate should be at their highest levels.