Groove Design Research Articles

Failure analysis of additively manufactured PLA with different morphological arrangements in erosive flow

This study investigated the impact of water-sand slurry on Polylactic Acid (PLA) in Fused Deposition Modeling (FDM), exploring different morphologies and variables using Taguchi design. Variables included three designs (D1: Flat, D2: Groove, D3: Square groove), slurry concentrations (1%, 3%, 5% by weight), and impact angles (60°, 75°, 90°). Surface damage observed on PLA included cracks, micro-cutting, flakes, and craters due to erosion. The Groove design (D2) showed superior erosion resistance compared to Flat (D1) and square groove (D3). Analysis identified slurry concentration (64.68%) as the primary influencer of erosion, followed by design (23.80%) and impact angle (10.56%). These findings highlight the importance of optimizing FDM parameters to enhance PLA durability against abrasive conditions.

Thermal management performance of a novel elliptically grooved flat heat pipe system embedded with internally cooled condenser

Flat heat pipes (FHPs) with rectangular groove wick structures fail to sufficiently uplift the working fluid’s liquid meniscus to cover the upper sides of the groove walls due to the vertically flat wall design. This results in the formation of non-evaporative zones, particularly in the evaporator region, leading to elevated wall temperatures at high heat loads. To address this issue, a novel FHP with elliptical grooves as wick is designed and tested across heat loads ranging from 30 to 360 W. Elliptical groove depths of 0.5 mm and 0.7 mm are evaluated and compared to FHPs with rectangular grooves. Results showed that at 360 W, the 0.7 mm depth elliptical grooves resulted in 6.5 % reduction in evaporator wall temperature and 27.8 % reduction in thermal resistance, along with 31.5 % enhancement in effective thermal conductivity compared to rectangular grooves. The curvature of the elliptical grooves, combined with enhanced surface tension effects of the working fluid, efficiently uplifted the liquid meniscus to cover the upper wall of the groove, minimizing non-evaporative zones. Additionally, FHPs with elliptical grooves demonstrated lower entropy generation, indicating higher thermal efficiency. Consequently, FHPs with elliptical groove designs are concluded to be an efficient and suitable solution for the thermal management of miniaturized electronic devices.

The important factors for structure and mechanical properties in the repair of iron base metal component by thermal spray and welding processes

Cast iron is widely used in the manufacturing industry due to its high strength and wear resistance properties. However, cast iron's brittle nature results in frequent failure of cracks during formation or use. Among the repair methods that can be used are thermal spray and the welding process. Even though both welding and thermal spray have been implemented for various metal repairs processes, however very limited technical reports as well as scientific papers are found for this topic. Therefore, the optimum condition of metal repair by both processes is still needed to be explored. The present works focus on the comparison between thermal spray and welding method for cast iron repairs purposes. In the experiment of thermal spray process focus has been given in optimizing spraying distance on microstructure and hardness properties. On the other hand, in the welding experimental works focus has been given on the influence of groove design on microstructure and hardness. Each research variable is carried out to obtain optimal crack repair results. It was observed that thermal spray process produces less Heat Affected Zone (HAZ) area compared to the welding process therefore having less critical area. The highest hardness value of thermal spray method is 101.33 shown by 30 cm spraying distance. Meanwhile, the highest hardness value of HAZ area of welding method is 600 HV shown by specimen A. It was obtained that from the present experimental works, thermal spray process produces better results than welding process. However, the value of the specimen hardness produced by the welding and thermal spray method depends on the type of coating material used

Comparative study of electrogas and shielded metal arc welding processes on steel A537 welded joints

In this research, the electro-gas welding process was compared with a shielded metal arc welding process for welding steel A573 from a mechanical properties point of view. Visual and radiographic inspections confirmed the soundness of weldments produced by electro-gas welding and shielded metal arc welding techniques. Various assessments were performed, including hardness, tensile strength, V-notch impact toughness, macrostructure, microstructure, and electrochemical tests. The mechanical properties of the two welding processes were closely matched, with an average tensile strength of 590 MPa for electro-gas welding and 585 MPa for shielded metal arc welding. Furthermore, the influence of welding variables, such as groove design and heat input, on the welded joints’ quality, mechanical properties, and electrochemical behavior was thoroughly examined. Dilution estimates, particularly for the electro-gas welding process, were around 35%, and a significant similarity was observed between the chemical composition determined through dilution calculations and that obtained from chemical analysis using an arc spark emission spectrometer. Notably, the electro-gas welding process demonstrated exceptional productivity, surpassing the shielded metal arc welding process by more than elevenfold. The optimum welding parameters for the electro-gas welding process were identified to achieve superior mechanical properties, low corrosion rates, and reduced consumption of the welding electrodes. This included adopting a single V type and groove angle of 30° instead of 60°, resulting in a 23% reduction in economic costs. Selecting an appropriate heat input within the range of 12 to 14 kJ/mm further contributed to enhancing overall welding efficiency.

Analysis and structural optimization of tree-type dynamic pressure groove mechanical seal performance

Abstract This study investigates the influence of the order and groove ratio of a tree-shaped groove on the sealing performance of a mechanical seal system using numerical simulations. A three-dimensional geometric model of the tree-shaped groove is established using SOLIDWORKS, and the mesh is divided in ANSYS Meshing before being imported into Fluent software for analysis. The single-factor experimental method is employed to evaluate the impact of different parameters on the opening force and leakage rate by varying one parameter while keeping others constant. The simulation results reveal that in the low-speed range, the tree-shaped groove with a groove ratio of 3:4:5 exhibits a larger opening force. Conversely, in the high-speed range, the three-stage tree-shaped groove with a groove ratio of 1:1:1 demonstrates a lower leakage rate and a larger opening force. The findings highlight the significant impact of the order and groove ratio of the tree-shaped groove on the sealing performance of the non-contact mechanical seal. The three-stage tree-shaped groove outperforms the second and fourth stages in terms of mechanical sealing performance, particularly in regard to the opening force. This study provides valuable insights into optimizing the design of tree-shaped grooves in mechanical seal systems to enhance their overall performance and efficiency.

A sustainable MXene/PVA/CNFs@Fabric roll-based 3D photothermal evaporator integrating efficient evaporation and anti-pollution design

Solar-driven interface evaporation is an effective approach towards achieving clean seawater desalination. The focus of research in this field lies in attaining sustained, stable, and efficient steam generation during the photothermal evaporation process. In this study, the proposed MPFR evaporator featured a 3D spiral conical groove design combined with a hydrophilic MXene/PVA/CNFs functional layer, which effectively enhanced light absorption (>97 %) through multistage reflection and absorption. This facilitated a body-phase absorption/body-phase heating process that effectively reduced the surface temperature of the illuminated area compared to a flat evaporator. Consequently, this was conducive to the absorption of environmental heat to supply water evaporation. Under 1.0 sun illumination, the evaporation rate and evaporation efficiency of MPFR-4 evaporator reached 3.84 kg m−2·h−1 and 156.29 % respectively. The introduction of the hydrophilic functional layer not only enabled water activation but also enhanced the water supply capacity of both yarn and fabric on the evaporator surface, forming a water layer that promoted high-salinity water diffusion and salt crystal dissolution while effectively inhibiting salt crystal pollution. Moreover, this water layer imparted oil-repellent characteristics to the evaporator, enabling it to resist oil-pollution from sea surfaces as well. Thus, this work provided novel insights into designing highly efficient and anti-pollution solar thermal evaporators that drove advancements within green and sustainable water generation.

Numerical Simulation of Fishtail Biomimetic Groove for Dry Gas Seals

In recent years, the use of dry gas seal technology in high-end industrial applications has become increasingly widespread. Existing research has primarily focused on unidirectional grooves. This study introduces an innovative approach by incorporating bidirectional grooves inspired by the biomimetic design of a carp tail, aiming to enhance sealing performance. The analysis of flow-field characteristics was conducted using Fluent software to evaluate the effect of different groove designs on sealing efficacy. The results indicate that curved grooves are more effective in directing gas flow and reducing fluid dynamic losses, thus improving the overall sealing efficiency. In particular, the outer-curved carp-tail groove exhibited superior dynamic pressure effects and reduced pressure drops across various operating conditions. The optimal radial dam-to-groove width ratio ranged from 3.8 to 4.1, and the optimal groove depth ranged from 6.5 to 9.6 μm. This investigation focused on the design and performance evaluation of biomimetic carp-tail grooves for dry gas seals, presenting a novel groove configuration for end-face sealing and further advancing the theoretical understanding of dry gas seals.

Structural design and simulation of herringbone groove bearing lubricated with liquid metal

Abstract We designed a novel herringbone groove sliding bearing suitable for gallium-based liquid metal lubrication, taking advantage of the excellent fluidity, high thermal conductivity, and strong stability of gallium-based liquid metal at room temperature. We used the finite element method to analyze how eccentricity affected the bearing pressure variation and chose the best structural parameters by comparing how different groove parameters affected the peak pressure and carrying capacity. The results show that the herringbone groove reduces bearing friction resistance and causes the bearing pressure variation to exhibit a herringbone pattern. The herringbone groove structural parameters have a significant impact on the peak pressure and carrying capacity of the bearing. The gallium-based liquid metal bearing works well when the herringbone angle is 50°, the groove depth is between 15 μm and 25 μm, and the groove ratio is between 0.7 and 0.9.

Using Gaussian process regression for building a data-driven drag loss model of wet clutches

Drag loss calculation models support designing low-loss wet clutch systems and determining drivetrain efficiency. Available numerical models require high computational effort, whereas analytical models provide only limited accuracy. In contrast, data-driven models unite the advantages of fast and effective drag loss prediction and, thus, enable practice-oriented development. Therefore, this study aimed to build a data-driven model of the wet clutches’ drag losses, enabling predictions with low computational effort and, at the same time, sufficient accuracy while taking seven relevant influencing parameters into account. The dataset used originates from prior research projects that experimentally investigated the wet clutches’ drag loss behavior under consideration of various influencing parameters. Different machine learning algorithms were considered for model building, and it was found that Gaussian process regression best met the requirements of flexibility and interpretability. Four sub-models were built to predict four characteristic drag loss values based on the model input parameters of mean diameter, diameter ratio, number of gaps, clearance, dynamic viscosity, oil level, and groove design. Subsequently, the predicted characteristic drag loss values can be used as support points for approximating the drag loss curve. The sub-models show high R² values, ranging from 0.84 to 0.95, indicating a high model performance. The mean relative error of the sub-models was used for evaluating the models’ performance from an engineering perspective, ranging from 4.6 % to 14.2 %. The drag loss model was also validated based on documented knowledge of wet clutches’ drag loss behavior. The model enables the prediction of the drag loss curve within a few split-seconds and, simultaneously, with sufficient accuracy.

Thermal Cavitation Effect on the Hydrodynamic Performance of Spiral Groove Liquid Face Seals.

Cavitation in micro-scale lubricating film could be determined by the fluid's thermal properties, which impacts the hydrodynamic lubrication capacity dramatically. This study aimed to novelly investigate the impact of the thermal cavitation effect on the hydrodynamic performance of liquid face seals, employing the compressible cavitation model, viscosity-temperature effect, and energy equation. The finite difference method was adopted to analyze the thermal cavitation by calculating the pressure and temperature profiles of the lubricating film. The working conditions and geometric configuration of liquid face seals under different thermal cases were further studied to explore their effects on sealing performance. The results showed that thermal cavitation could reduce the temperature difference of liquid film at high speeds, and cavitation would be weakened under temperature gradients, which further dropped off the hydrodynamic performance. Contrary to the leakage rate, the opening forces tended to be lower with the increasing seal pressure and film thickness under high-temperature gradients. Furthermore, apart from the spiral angle of grooves, the hydrodynamic performance exhibited significant variation with increasing groove depth, number, and radius at high-temperature gradients, which meant that the thermal cavitation effect should be considered in the design of geometric grooves to obtain better hydrodynamic performance.

A review on retrofitting concrete members with near‐surface mounted‐fiber reinforced polymer composites

AbstractIn an era flooded with a multitude of studies investigating the performance of concrete structures retrofitted using fiber‐reinforced polymer (FRP) materials, this review addresses the critical need for a comprehensive overview of the retrofitting of concrete members using near‐surface mounted (NSM)‐FRP composites, aiming to save time and effort while providing engineers and research community with valuable resources relevant to the field. This review focuses on the key factors influencing both the flexural and shear retrofitting processes of reinforced concrete (RC) beams, such as the percentage, type, size and geometry of NSM‐FRP reinforcement, as well as groove design, groove‐filling materials and beam depth. Moreover, the paper explores the failure modes associated with each retrofitting type, for example, debonding failures, shear/flexural failure and rupture of steel or NSM‐FRP reinforcement, to name a few. The review also delves into the bond behavior of NSM‐FRP‐bonded joints, examining factors, such as the bonded length, surface texture of NSM‐FRP reinforcement and type of bonding agent, which would affect the bond behavior and strength of the joints. The failure mechanisms associated with the bonded joints, such as interfacial bond failure, FRP rupture and splitting of the adhesive cover, are also highlighted. Finally, this compilation aims to guide engineers and researchers by offering a critical and comprehensive database for optimal designs, further development and suggesting future research directions.

Groove design optimization of femoral heads in solid hip implants: Study on stress distribution and total deformation using FEA and full factorial design

Hip replacement surgery is a common procedure that relies on the implant's design to withstand daily activities. This study aims to investigate the impact of different surface groove designs on the performance of solid hip implants using finite element analysis (FEA) and optimization techniques. The study evaluates the influence of grooves on the stress distribution and total deformation of the implant, considering three designs: no grooves, horizontal grooves, and vertical grooves on the surface of the femoral head. The simulations were conducted using Ansys Mechanical, and the optimization process was carried out using the general full factorial design method in Minitab software. The results demonstrate that the groove design significantly affects the stress distribution and wear of the implant. The vertical groove design shows better overall results, indicating the best performance. The study also evaluated the influence of force on the performance of the implant, with different load range. The optimization process using the general full factorial design method revealed that the optimal groove design was a vertical model with an optimized groove depth and width. These findings offer valuable insights into the impact of surface groove designs on the performance of solid hip implants, leading to better patient outcomes and longer implant lifespan. Overall, this study provides a comprehensive understanding of the effect of surface groove design on the performance of solid hip implants.

Robotic wire-based friction stir additive manufacturing

High axial force requirement for existing friction stir additive manufacturing technologies is a substantial obstacle to manufacturing of complex reliable components by high-freedom robots. Here, we proposed a new robotic wire-based friction stir additive manufacturing (R-WFSAM) method, characterized by paraxial feeding wires and pre-plasticization process, to enable the formation of deposited layers with significantly low force. The spiral groove design on the screw tool facilitates the pre-plasticization of materials prior to deposition and the continuous extrusion of the material, reducing axial force and diminishing the reliance on high-stiffness equipment for solid-state relevant technologies. Fully dense aluminum alloy components on the 2D plane and 3D curved surface by hybrid position/force control were successfully manufactured. The sufficient material flow and material mixing behavior during deposition on the plane induced by the multi-pin design strengthened the interfacial bonding. Homogeneous and fine grains were also achieved due to severe plastic deformation. The R-WFSAM Al-Si alloy component possessed an ultimate tensile strength of 230±5 MPa and an uniform elongation of 28.1±1.0 %, exhibiting excellent isotropic mechanical properties. This method provides a novel approach for manufacturing large-size complex structural components with high flexibility and field re-manufacturing.

Application of 3D Imaging for Analyzing the Chip Groove Shapes of Cutting Inserts

An effective chip formation process is significant for an efficient metal-cutting process. Long continuous chips can lead to scratches on the machined surface, increasing the risk to operator safety and stability of the machining process. The use of chip grooves on cutting inserts allows for control of the chip formation and breaking process during machining. The shape of the rake surface and the design of the chip groove also affect the efficiency of the machining process. The article presents the use of 3D imaging to analyze changes in the selected chip groove shapes depending on the cutting depth ap = 0.10, 0.25, and 0.50 mm and the angular location of the cutting insert relative to the machined surface of the workpiece (i.e., major cutting-edge angle K = 60° and K = 90°). The analysis methodology was based on the use of 3D image registration and surface shape modeling. In the analysis based on the 3D imaging presented, the novelty was the adaptation of methods typically used to map and model the terrain surface, which have not been used previously in cutting processes. The evaluation of the shape of the chip groove surface was carried out using, e.g., watershed maps and 3D surface maps. The obtained results indicated a significant influence of the cutting depth and major cutting-edge angle on the surface shape, profile, and length of the chip former; chip groove volume; and the theoretical contact area of the formed chip with the cutting insert. It was observed that for small depths of cut, i.e., ap < 0.25 mm, the chip-curling process may be difficult due to the flattened shape of the rake surface. In addition, the influence of the convexity of the rake surface of the cutting insert on the chip formation process was demonstrated. The results of the experimental research that verified the conclusions are presented. The developed results may be useful in the process of selecting the parameters and conditions of the metal finishing through use of tools with a shaped rake surface.

Metallurgical, mechanical, and corrosion behavior of AISI 304L joints welded using variable arc energy inputs and subjected to thermal aging

The effect of three levels of welding arc energy input on the metallurgical, mechanical, and corrosion behavior of AISI 304L stainless steel was studied with the aim of investigating and recommending the most useful range of process parameters for improved performance of engineering structures made from this industrially important alloy. The gas tungsten arc welding process was employed, and all the joints were butt-welded using a single-V groove design. With an increase in heat input, the δ-ferrite phase changed from lathy to vermicular, besides the heat-affected zones of all the welds exhibiting grain coarsening effects. Postweld thermal aging led to the preferential occurrence of carbides in the interdendritic regions, which degraded their corrosion performance. Thermal aging did not affect the tensile strength of these welds, but their ductility was significantly impacted. The extent of segregation of Cr and C, especially, was observed to be the least in the case of low heat input welds. This study establishes that while designing welding procedures for AISI 304L structures, low welding arc energy should be used as it promotes better mechanical as well as corrosion properties.

Comparison of V groove design on mechanical performance and fracture behaviour in TIG welding of 5754-H111 aluminium alloy

The aim of this study is to enhance the performance and effectiveness of welding 5mm thick plates with different groove designs and investigate their post-effects on material properties. Specifically, the study compares single V and double V butt joints of 5mm thick AA5754-H111 strain-hardened aluminium alloy using Tungsten Inert Gas (TIG) welding with ER5356 (Al-Mg) filler rod. Two types of weld grooves, single V groove and double V groove were utilized to examine the microstructure and character of the weld and to study the effect of heat distribution. The average Vickers hardness values were observed to be 78.2HV in the double V groove of weld zone compared to the 76.6HV in single V groove weld zone. The tensile strength of single V and double V groove were 210 and 207 MPA respectively. The results showed that the failure location of all weld samples was in the fusion zone (FZ) and exhibited brittle fracture. The microstructure of the weld fusion zone revealed the presence of porosity in various sizes, which was also observed in the fractography images of tensile failed samples. Moreover, the microstructure studies exhibited clear variations in the fusion, intersection, and heat-affected zones. The formation of particles was found to differ in the weld fusion zone at various locations due to changes in the V groove welding method.

Influence of rotor impeller structure on performance improvement of suspended axial flow blood pumps.

The hydrodynamic suspension structure design of the axial blood pump impeller can avoid the problems associated with using mechanical bearings. However, the particular impeller structure will impact the hydraulic performance and hemolysis of the blood pump. This article combines computational fluid dynamics (CFD) with the Lagrange particle tracking method, aiming to improve the blood pump's hydraulic and hemolysis performance. It analyzes the flow characteristics and hemolysis performance inside the pump. It optimizes the taper of the impeller hub, the number of blades, and the inclination angle of the circumferential groove at the top of the blade. Under certain rotational speed conditions, an increase in the taper of the impeller hub or the number of blades can increase the pumping pressure of a blood pump, but an increase in the number of blades will reduce the flow rate. The design of circumferential grooves at the top of the blade can increase the pumping pressure to a certain extent, with little impact on the hemolysis performance. The impeller structure is optimized based on the estimated hemolysis of each impeller model blood pump. It could be seen that when the pump blood pressure and flow rate were reached, the optimized impeller speed was reduced by 11.4%, and the estimated hemolysis value was reduced by 10.5%. In this paper, the rotor impeller structure of the blood pump was optimized to improve the hydraulic and hemolytic performance effectively, which can provide a reference for the related research of the axial flow blood pump using hydraulic suspension.

Single-step self-punching lockbolt process for aluminum sheets without pre-hole

For the mechanical joining of aviation-grade aluminum alloys, the study introduces an innovative approach using self-punching lockbolts. This method involves the utilization of a profiled collar and a specially designed bolt to seamlessly join EN AW-2024 T42 aluminum sheets, up to a thickness of 8.0 mm, without the need for pre-holes. In this process, when the aluminum sheets are punched, the collar undergoes slight deformation, effectively functioning as a die. Subsequently, the collar is systematically formed by applying increased force. By fine-tuning the design of the bolt ring groove, it becomes feasible to create a joint with a bolt length that accommodates sheet thickness variations of up to 1.6 mm. To facilitate this development, the joining process was meticulously designed and the auxiliary part was optimized with the aid of numeric simulation tools. The process simulation enabled the identification of deformation mechanisms within the collar, accounting for both geometry and material properties. The important factors influencing collar deformation include collar thickness, shoulder height, and shoulder diameter. Furthermore, experimental investigations were conducted to assess the mechanical properties of the joint and evaluate how material-specific factors influence joint failure behavior. It can be seen that the formation of the mechanical fit is influenced by the ring groove depth and the fitting position. The joints failed under shear tensile load exclusively at the bolt head.

The design of chip breaking grooves for spade drill inserts

A chip breaking groove was designed on a spade drill insert to break chips. The effects of the anti-chip angle, width and height of chip breaking groove on the chip curl radius were investigated with simulations and drilling experiments. The forces acting on the chip were analyzed to clarify the chip breaking processes. The chip breaking process of a spade drill insert with chip breaking groove was simulated with the finite element technique to study the chip breaking mechanism. The calculation formulas for calculating the width, height and radius of the chip breaking groove were established. The research results show that the chip curl radius is affected by the chip breaking groove parameters. The chip curl radius increases with the anti-chip angle but decreases as width decreases or height increases. When the values of anti-chip angle, width and height of chip breaking groove reach thresholds, the chip wind or piling phenomenon will occur during the drilling experiments. The formulas for calculating chip breaking grooves are feasible. A design method of chip breaking grooves for spade drill inserts is proposed. Spade drill inserts whose chip breaking groove parameters are calculated according to formulas of the width, height and radius can effectively break chips at different drilling parameters.

Effects of Surface Textures Created Using Additive Manufacturing on Shear Bond Strength Between Resin and Zirconia.

This investigation aimed to assess the impact of additive manufacturing-generated surface textures on zirconia bond strength. Zirconia samples (n = 144) fabricated using digital light-processing (DLP) technology were categorized into 6 groups according to the type of surface conditioning (group NN: no designs, no air abrasion; group NY: no designs, with air abrasion; group GN: groove designs, no air abrasion; group GY: groove designs with air abrasion; group HN: hexagon grid, no air abrasion; group HY: hexagon grid, with air abrasion). Composite resin cylinders were cemented to the treated zirconia surfaces with dual-curing, self-adhesive resin cement (Clearfil SA Luting). The shear bond strength (SBS) was tested after water storage for 3 days or 3 days with an additional 10,000 thermocycles. The zirconia samples fabricated using DLP technology have high accuracy. The SBS of the NY, GY, and HY groups did not significantly differ after 3 days, and neither did the SBS of the NN, GN, and HN groups. The NN, NY, and HY groups exhibited reduced SBS compared to their initial values following artificial aging, while the SBS of the remaining three groups were not diminished. The GY group obtained the highest SBS value after aging. Printing grooves with air abrasion can improve the bond strength.