Nowadays, linear machines have more developed for high power applications such as longdistance transportation. But, their expensive investment and some technical problems are major challenges of these technologies. Here, a linear flux switching machine (LFSM) with segmented secondary is studied. These fluctuations, in other words, detent force have a negative impact on machine performance. The effect of these issues can be notably reduced with a suitable design. In this paper, a FEM-based Analytical model is presented for a linear flux switching machine. The results of analytical model are verified by FEM Simulations and then a control method is proposed to reduce fluctuations of the thrust force.

Estimation Face pressure and Thrust force of TBM are one of the basic requirements in mechanized boring. In case of incorrect estimation, there is a possibility of face instability, shrinkage of shield and machine stuck, which leads to costs increasing and prolonged completion time of project. The Kani Sib tunnel consist of two sections of rock and alluvium. Due to the presence of underground water, low mechanics rock parameters and high overburden on alluvial section, this section is one of the most dangerous parts of the tunnel. For that reason, in this paper, estimation of face pressure and trust strength in mechanized excavation of the alluvial section has been studied. At first, in order to do this, required face pressure for maintenance was calculated by analytical method and verified by numerical method. After checking the accuracy of selected pressure, the pressure on the shield and thrust force, which includes force applied from face, shield fraction force, disc cutter force and tension force of the shield, was determined.

Developing customized drilling processes that minimize damage and improve overall performance in natural fiber composites relies on a thorough understanding of their drilling performance and potential damages. This study explores the variations in delamination and thrust force in a redmud-filled polyester composite reinforced with coconut sheath fibers. Employing a Taguchi factorial design, the experiment investigates the impact of drilling parameters, including drill diameter, spindle speed, and feed rate. The ANOVA analysis is employed to validate the experimental results. The findings indicate that increased feed rates and spindle speeds contribute to elevated thrust forces and delamination, influenced by the composite's inherent brittleness due to the addition of red mud. Among the drilling parameters, feed rate exerts the most significant influence on thrust force (ca. 30%), while the point angle has the greatest impact on delamination (ca. 60%). The analysis of drilled hole surfaces reveals matrix cracks, fiber extraction, and matrix smearing, underscoring the importance of optimizing drilling parameters, selecting appropriate tools, and implementing effective cooling methods to improve the overall surface finish and quality of drilled fiber composites. The research has the potential to aid in the development of strategies to minimize damages and enhance overall surface quality; ultimately, it contributes to advancing knowledge in materials science and engineering, with applications in the manufacturing and utilization of natural fiber composites across diverse industries.

Metal composites have received attention from various industries due to their excellent properties, such as a high strength-to-weight ratio and wear resistance. However, due to the presence of hard and abrasive particles, the challenges have always faced machining. Therefore, studying the effective parameters in the machining of these materials is very important. Drilling is one of the most common and widely used methods in the industry. In this study, the Response Surface Method (RSM) and Central Composite Design (CCD) were used to model, optimize, and analyze the effects of machining parameters. Aluminum composite with AL356 alloy reinforced with 25 micrometers of silicon carbide and 45 micrometers of mica mineral, as well as a 6 mm diameter carbide drill, were used for the experiments. According to the results, with an increase in the drilling speed, the drilling forces increased and the surface roughness decreased. Additionally, increasing the feed rate increased forces and surface roughness. With an increase in the volume fraction of SiC reinforcing particles, the drilling forces and surface roughness increased and decreased, respectively. By analyzing the data obtained from the experiments, the best combination of values was found to minimize the surface roughness and axial force at the same time. The best combination of parameters was found to be: a spindle speed of 1855 rpm, a feed rate of 50 mm/rev, and a weight percentage of 15% SiC

Minimum quantity lubrication (MQL) is a promising solution as an alternative to conventional flood cooling and dry machining. This study investigates the enhancement of drilling performance through the application of hybrid (Al2O3 + CuO) and unitary (Al2O3) nanofluids in the MQL system, focusing on thrust force, torque, friction coefficient, and the final surface quality. A full factorial design of experiments was employed to evaluate the effects of lubrication type, nozzle configuration (number, geometry, and outlet diameter), and their interactions under identical conditions. Results demonstrated that hybrid nanofluids outperformed unitary nanofluids, achieving reductions of 51% in thrust force, 56% in torque, and 42% in friction coefficient compared to dry machining when using four rectangular nozzles with a 1.5 mm outlet. Increasing the number of nozzles from one to four enhanced lubricant distribution, reducing thrust force, torque, and friction by 22%, 23%, and 38%, respectively. Rectangular nozzles with a 1.5 mm outlet proved effective due to superior spray coverage, while ANOVA identified number of nozzles and nozzle geometry as the most influential parameters. Surface quality improvements, including reduced burrs and cracks, were observed with hybrid nanofluids, enhancing precision and fatigue life. Multi-criteria optimization via TOPSIS confirmed the hybrid nanofluid MQL system with four rectangular nozzles (1.5 mm) as the most effective configuration. These findings underscore the potential of advanced MQL strategies to improve machining efficiency, tool life, and surface integrity in green manufacturing.

Epoxy matrix composites reinforced with carbon dot nanoparticles are increasingly utilized in industries due to their enhanced mechanical, thermal, and electrical properties. Drilling, a critical machining process for assembling these composites, often induces defects such as delamination and stress concentration, impacting structural integrity. This study systematically investigates the influence of machining parameters—spindle speed, feed rate, and drill bit diameter—on the thrust force during drilling of carbon dot-reinforced epoxy composites. A full factorial design of experiments was employed, with thrust forces measured using a high-precision load cell. Statistical analysis, conducted via Minitab software, revealed that drill bit diameter is the dominant factor, contributing 66.18% to thrust force variation, followed by spindle speed (19.90%) and feed rate (7.16%). The regression model, with an R-squared value of 98.90%, highlights significant linear and nonlinear interactions among parameters. Increasing feed rate and tool diameter markedly elevate drilling forces, while higher spindle speeds slightly reduce them. The incorporation of carbon dots up to 1 wt.% reduces thrust force by enhancing interfacial bonding, though excessive concentrations may induce embrittlement. Optimization results identify the ideal settings as spindle speed at 2500 rpm, feed rate at 10 mm/min, drill bit diameter at 0.3 mm, and carbon dot concentration at 1 wt.%, achieving a minimal thrust force.

One of the most important machining processes in the field of orthopedic surgeries and biomedical engineering is the drilling process. Applying excessive force on the bone tissue can cause cracking and damage bone tissue during the drilling process. In this paper, an improved analytical model is produced based on early work done by Bono and Ni, Chandrasekhar an, and Lee to predict the thrust force in the bone drilling process. In this model, the cutting action at the drill point is divided into three regions: the primary cutting lips, outer portion of the chisel edge (the secondary cutting edges), and inner portion of the chisel edge (the indentation zone). All three regions have been investigated for the cutting process by the analytical model. In order to validate the model, some experiments are performed on the fresh bovine bone. Feed rate and rotational speed are adapted as the effective parameter in the drilling process, The statistical model to obtain the mathematical model and provide interaction diagrams of input variables experiments, to response surface methodology and experimental investigation of bone drilling have been offered. Comparing the analytical model and experimental results shows good agreement. From both analytical model and experiments, it can be concluded that with decreasing feed rate and increasing rotational speed, thrust force on the bone tissue decreases.

Bone drilling process is the most prominent process in orthopedically surgeries and curing bone breakages. It is also very common in dentistry and bone sampling operations. Due to complexity of the material that is machined, bone, and the sensitivity of the process, bone drilling is one of the most important, common and sensitive processes in biomedical engineering field. Developed a three-axis robotic bone-drilling system and mechatronic bone-drilling tools improved the orthopedic operations. Furthermore, imposing higher forces to bone might lead breaking or cracking and consequently serious damage in bone. In this paper a mathematical second order linear regression model is introduced to predict process force behavior during bone drilling process as a function of tool drilling speed, feed rate, tool diameter and effective interactions. This model can predict carefully force behavior during bone drilling within the acceptable range. Moreover, applying design of experiments, modeling and optimization of effective parameters using response surface method in bone drilling process optimized drilling speed, feed rate and tool diameter were obtained to minimize force. Results show that to minimize force increasing the drilling speed would decrease the thrust force, whereas decreasing the feed rate and tool diameter would decrease the Thrust force.

The goal of this paper is presenting the optimal formulas and calculation of cutting forces and torque in drilling process. The presented mathematical models are developed to predict the thrust and torque forces at the different regions of cutting on a twist drill. The geometry of the drilling process (chipload, cutting angles,..) was exploited for developing this models. The input to the model is the machining conditions and the tool geometry and the model predicts the thrust and torque profile along the cutting lips and the chisel edge of the twist drill.