Papers by Keyword: Pressure Distribution

Abstract: This study investigates the structural response of blank-holders (BHs) equipped with spatially distributed magnetorheological (MR) actuators for adaptive deep drawing. While MR actuators provide fast, independent, and high-resolution force modulation, their effectiveness depends critically on the BH’s ability to transmit spatially differentiated loads without excessive diffusion or unrealistic stress localization. The relationships between BH stiffness, actuator spacing, and pressure localization at the sheet interface remain only partially understood, limiting the implementation of distributed blank-holding strategies. To address this gap, a comprehensive finite element (FE) framework is developed, combining a full closed-cup deep-drawing model with a complementary simplified configuration that isolates local deformation mechanisms under single-actuator loading. Parametric analyses examine the influence of BH thickness, local actuator force, and actuator spacing on stress distribution, localization radius, and overlap between adjacent load paths. Results show that BH thickness is the dominant factor governing spatial resolution: thinner BHs enable sharp pressure localization, whereas thicker ones diffuse local loads and suppress stress peaks. The spacing between actuators must therefore be selected as a function of BH stiffness to avoid stress-free regions while preserving distinct pressure footprints. For the reference industrial configuration (60 mm BH thickness), an actuator spacing of approximately 150 mm achieves the optimal compromise between localization capability and continuous sheet support. The proposed framework establishes quantitative design criteria for BH geometries compatible with MR-based adaptive forming and supports the development of next-generation blank-holding systems offering enhanced process stability, reduced scrap, and improved material-flow control.

Abstract: A process when different materials are combined to produce a product with multiple layers is called co-extrusion. During this process, polymers are melted in separate machines and then extrudate from different die channels. Once these channels converge, the polymers meet and flow through a single channel. The surface where the two fluids face is called “interface”. It is crucial to maintain the interface's uniformity and stability in order to achieve the desired multi-layered structure. Most of the issues in co-extrusion are related to issues that can be classified into two categories such as polymer encapsulation/interfacial distortion and die swell. To solve these problems, designers focus on improving the interface's stability. This paper examines effects of cross-section modification of the two-channel feedblock on the interface location and velocity and pressure distributions of the flow. The ANSYS software was used to simulate the co-extrusion of polymers, LLDPE and HDPE, in two-channel feedblock with rectangular, circular, and straight slot cross-sections. The results show that sharp corners increase the thickness of dead zones, while rounding them decreases the thickness. Additionally, stadium-shaped (or straight-slot) cross-section channels can move the flow with a higher maximum velocity and thinner boundary layer combining the results of rectangular and circular feedblocks.

Abstract: In this study, the authors evaluated pressure distribution on a backing plate in friction-stir processing (FSP) utilizing an embedded pressure pin connected to a load sensor. They conducted FSP on aluminum alloy plates repeatedly offsetting the path-lines from the center of the pin and recorded change of forming pressure with tool position, which was compiled from the bearing load of the pin. The authors mapped the results to visualize the two-dimensional contact pressure distribution on a backing plate during FSP. They then compared the height distribution of the wall fabricated by friction-stir forming (FSF) utilizing a die having a groove with the observed distribution of pressure. Consequently, maximum pressure was observed beneath the rim of the tool probe at the retreating side (RS), and the highest points of the wall were observed at the RS.

Abstract: One of the most effective methods for descaling hot-rolled steel products is performed using highpressure flat jet nozzles. These descaling nozzles are arranged in rows in hot rolling mills and areset in such a way that each adjoining pair of nozzles creates an overlapping area of water jet streams.Good homogeneity of the pressure distribution over the width of the hot-rolled plate is often used as anindicator of quality of the homogeneity of descaling. The presented laboratory measurements examineone pair of adjoining nozzles with a particular focus on the pressure distribution in the overlappingarea. This paper deals with one particular setting of a pair of descaling nozzles with zero offset anglesfor the jet streams. A measured pressure distribution and an outcome of an erosion test on an aluminumplate are presented and discussed. The erosion test shows that spots with higher pressures do notnecessarily result in a higher amount of removed material during an erosion test. The erosion test differs from the expected outcome in such a way that a detailed discussion of this phenomenon is outlined with possible explanations.

Abstract: This paper presents the theoretical study and analyzes the comparison of porous structures on the performance of a couple stress fluid based on rough slider bearing. The globular sphere model of Kozeny-Carman and Irmay’s capillary fissures model have been subjected to investigations. A more general form of surface roughness is mathematically modeled by a stochastic random variable with non-zero mean, variance and skewness. The stochastically averaged Reynolds type equation has been solved under suitable boundary conditions to obtain the pressure distribution in turn which gives the expression for the load carrying capacity, frictional force and coefficient of friction. The results are illustrated by graphical representations which show that the introduction of combined porous structure with couple stress fluid results in an enhanced load carrying capacity more in the case of Kozeny-Carman model as compared to Irmay’s model.

Abstract: The northwest coast of Peninsular Malaysia had suffered various extents of structural damage and loss of 68 lives in the unprecedented 2004 Indian Ocean tsunami. Since then, the government of Malaysia concerns about the safety of civil engineering structures and human lives in coastal area. An experimental study was embarked on the formulation of tsunami force for onshore buildings in Peninsular Malaysia. Four downscaled rigid building models with various heights were subjected to probable tsunamis with three nominal wave heights and flow velocities. The wave pressures at front and back faces of building model were measured. The findings show that the front face wave pressure measured from the experiment is in good agreement with the wave pressure predicted using the equation proposed by Japanese researchers. The back face wave pressure distribution is found to be slightly higher than the hydrostatic pressure. The pressure distributions at the front and back faces were then proposed for the estimation of tsunami force on buildings in the northwest coast of Peninsular Malaysia.

Abstract: The porous discharge flow tube has been widely used in agriculture, water supply and drainage, ventilation, chemical and other fields. Flow characteristics directly affect the flow uniformity of the porous tube, thereby affecting the efficient use of it. The theoretical analysis and experimental study on the capacity of the porous tube’s discharge (flux of water) have the important project value and theoretical significance. In this paper,the total flow calculation formula is derived by the knowledge of hydraulics, the relation of discharge discount rate is calculated through dimensional analysis and the average single hole discharge formula is established based on some experimental data. The results of the test data and engineering data showed that the formula results and the test results are quite identical.

Abstract: The flow passage including supply hole of externally pressurized gas was investigated. The outlet velocity of supply hole, bearing number and supply pressure’s relationship were built. According to supply hole’s speed, supersonic or subsonic model was chosen to calculate bearing clearance’s pressure distribution. Bearing number’s effects on pressure’s distribution was also studied. The calculation result shows that at larger bearing number, supply hole’s speed is harder to be chocked. Both in supersonic and subsonic condition, larger bearing number produces lower pressure loss.

Abstract: To study the mechanism on the vortex resonance characteristics of the central-slotted box girders, the large-scale sectional model vibration measurement and pressure measurement are employed. This paper takes a long-span cable-stayed bridge over the Yangtze River as an example to conduct the wind tunnel tests of large-scale sectional model. The test results indicate that it is the inside maintenance rails located in the aerodynamic susceptible sites that cause the vortex-induced vibration (VIV) of bridge model. Accordingly, the inside maintenance rails are proposed to be moved towards the central axis by a certain distance. The static pressure test results show that when shifting the inside maintenance rails, the negative mean pressure at the soffit plate knuckle line will not change dramatically, the fluctuating pressures on the upwind and downwind inclined panels can be reduced, and the fluctuating energy will be dispersed without a consistent predominant frequency. Wind tunnel tests of modified section are conducted and the results show that the VIV of bridge model can be suppressed completely due to the shift of inside rails.

Abstract: The free-surface-pressurized-flow is a complicated water-air two phase flow in the spillway tunnel, which should be studied in the engineering practice. This flow pattern existed from open flow to pressure flow with the submerged depth increasing, which has obvious pulsing pressure. The flow transformation and pressure distributions were observed and studied in this paper.