The effects of punch angle in noise and force formation for sheet metal blanking process

The paper is concerned with the effect of punch angle (0°, 4°, 8°, 16°), sheet thickness (0.8, 2 mm), and punch speed (25, 37.5 mm / min) on the force formation and noise in the blanking of DP600 dual-phase steel sheet. The blanking experiments were carried out in a modular blanking die. The blanking force and noise variables were obtained simultaneously during the blanking using a load cell and noise measuring device, respectively. It was determined that the blanking force significantly decreased with an increasing punch angle, while noise formation decreased. The increase in the punch speed slightly increased the amount of noise while it did not affect the blanking force significantly.

Numerical Simulation and Parameter Analysis of Electromagnetic Riveting Process for Ti-6Al-4V Titanium Rivet

Electromagnetic riveting process (EMR) is a high-speed impact connection technology with the advantages of fast loading speed, large impact force and stable rivet deformation. In this work, the axisymmetric sequential and loose electromagnetic-structural coupling simulation models were conducted to perform the electromagnetic riveting process of a Ti-6Al-4V titanium rivet, and the parameter analysis of the riveting setup was performed based on the sequential coupled simulation results. In addition, the single-objective optimization problem of punch displacement was conducted using the Hooke–Jeeves algorithm. Based on the adaptive remeshing technology adopted in air meshes, the deformation calculated in the structural field was well transferred to the electromagnetic field in the sequential coupled model. Thus, the sequential coupling simulation results presented higher accuracy on the punch speed and rivet deformation than the loose coupling numerical model. The maximum relative difference of electromagnetic force (EMF) on driver plate and radial displacement in the rivet shaft was 34.86% and 13.43%, respectively. The parameter analysis results showed that the outer diameter and the height of the driver plate had a significant first-order effect on the response of displacement, while the platform height, transition zone height, angle, and transition zone width of the amplifier presented a strong interaction effect. Using the obtained results on the optimal structural parameters, the punch speed was effectively improved from 6.13 to 8.12 m/s with a 32.46% increase. Furthermore, the displacement of the punch increasing from 3.38 to 3.81 mm would lead to an 80.55% increase in the maximum radial displacement of the rivet shaft. This indicated that the deformation of the rivet was efficiently improved by using the optimal rivet model.

Development Of Microcontroller Based Punch Speed Measurements Tool Of Karate Athlete

This study aims to develop microcontroller-based punch speed measuring instrument for Karate Athletes. The research method used is research and development (research and development). The subjects in this study were karate athletes coaching FORKI (Indonesian Karate Sports Federation) Palembang City, which consisted of 30 senior athletes aged 17-25 years who were divided into two groups. Small group trials consist of 10 athletes and large group trials consist of 20 athletes. The technique of taking the research subject used a purpose sampling technique. The results showed that the development of a Microcontroller-Based Punch Speed Measurement Tool has a percentage level of validity of material test experts (karate) of 93%, the validity of media experts (Information Technology) is 2 people, 95% and 91%, respectively. exercise test and measurement experts by 97% so that the tool can be said to be feasible. The level of reliability in the small group trial was 0.994 with the High category. While the large group trial was 0.993 with a high category so that it was said that the level of reliability of the tool carried out in large group and small group trials had a high reliability category. Overall, this microcontroller-based punch speed measurement tool has been declared feasible to be used as a tool in calculating punch speed in meters/second (m/s) digitally. 993 with a high category so that it is said that the level of reliability of the tool carried out in large and small group trials has a high reliability category. Overall, this microcontroller-based punch speed measurement tool has been declared feasible to be used as a tool in calculating punch speed in meters/second (m/s) digitally. 993 with a high category so that the level of reliability of the tool carried out in large and small group trials has a high reliability category. Overall, this microcontroller-based punch speed measurement tool has been declared feasible to be used as a tool in calculating punch speed in meters/second (m/s) digitally.

Effects of Variable Punch Speed and Blank Holder Force in Warm Superplastic Deep Drawing Process

A cylindrical deep drawing test was conducted for the purpose of improving the drawability, product accuracy, and quality in warm deep drawing using a superplastic material with large strain rate dependence. Then, the effects of blank holding force (BHF) and punch speed (SPD) on the flange wrinkle behavior and wall thickness distribution were investigated by experiments and theoretical analysis. A Zn-22Al-0.5Cu-0.01Mg alloy superplastic material SPZ2 with a sheet thickness of 1 mm was employed as the experimental material, and a cylindrical deep drawing experiment with the drawing ratio (DR) of 3.1 and 5 was performed at 250 °C. A good agreement was qualitatively obtained between the elementary theory on the flange wrinkle limit, the fracture limit, and the experimental results. In addition, the authors examined each variable BHF and SPD method obtained from the theory and experimentally demonstrated that the variable BHF method has a great effect on uniform wall thickness distribution and that variable SPD has a great effect on shortening the processing time for superplastic materials. Furthermore, the authors demonstrated the effectiveness of the variable BHF/SPD deep drawing method that varies both BHF and SPD simultaneously.

Fabrication of aluminum bipolar plates with Archimedes' screw-shaped channels: a rubber pad forming process assessment

Bipolar plates are one of the most important components of polymer membrane fuel cells. In this manuscript, the rubber pad forming of aluminum bipolar plates with Archimedes' screw-shaped channels and draft angle of 90$$^\circ$$ ∘ has been investigated. Hence, all possible combinations of the process parameters were determined and corresponding experimentations performed in order to investigate the effects of the rubber hardness, punch speed and the hydraulic press force. In this regard, three rubber pads including polyurethane, silicone and natural rubber were used. Channel depth and thinning percentage in the corner of the channel are measured and the effect of each parameter is analyzed. Based on the results, the maximum channel depth was achieved using a silicone pad with a hardness of 60 Shore A. Using a rubber pad with a very high and low hardness number, both, reduces the depth of channel. Furthermore, as the punch speed increases, the channel depth increases and the thinning percentage, as well.

General Research on the Process of the Indirect Hot Stamping Ultra-High-Strength Steel

Aiming at the need for lightweight requirements of the components in the bus, combined with the advantages of the hot stamping ultra-high-strength steel, a new television (TV) bracket was proposed. The finite element (FE) simulation of the beam part in the TV bracket during the indirect hot stamping process was discussed. After two-stages of pre-forming, the blank was in good formability and without visible cracks. According to the FE simulation results, the punch speed, quenching force, and quenching time significantly affected the temperature, microstructure, hardness, and mechanical properties of the beam part during hot stamping. With the increase of the quenching force and quenching time, the martensite fraction of the beam part was increased. For the beam part, the punch speed should be at least 80 mm/s during the forming stage. For complete quenching, the quenching force should be above 1000 kN and quenching time should be up to 10 s. Based on the parameters from the FE simulation, the forming experiment of the beam part was discussed. Microstructure analyses and microhardness tests as well as tensile tests of the hot stamping beam part were performed. The results confirmed that the FE simulation of the beam part was reliable.

PENGARUH LATIHAN PUSH UP DAN LATIHAN BENCH PRESS TERHADAP KECEPATAN PUKULAN PADA PENCAKSILAT

This research is a field experimental study that aims to find out the different effects of push up and bench press exercises on punch speed on pencaksilat. The population was all students of the FOK UNG Sport Coaching Education Study Program and the sample involved were 60 people. But in accordance with the research design, two research groups were formed consisting of group A for push up exercises and group B for bench press exercises. Data analysis techniques used t-test at a significant level of 95%. Based on the results of data analysis, it can be concluded that: There is a significant effect of push up exercises on the speed of the punch on pencaksilat (to = 9,151> tt = 2,045). There is a significant effect of bench press training on punch speed on pencaksilat (to = 7,620> tt = 2,045). There is a significant difference in effect between push up and bench press exercises on punch speed on pencaksilat (to = 12,828> tt = 2,000).