This Research is aimed to predict the maximum varying blank holder force (VBHF) over the punch stroke in order to eliminate cracks on cup deep drawing product. The constant blank holder force during the process, it's frequently not capable to prevent cracking, effectively. Using the slab method with assuming a constant volume of material, the simple analytical approach of maximum VBHF, has been conducted under the failure deformation and cracking criteria on every stage punch stroke. The cracking criteria are based on the maximum strength of materials. Steel sheet of SPCD grade, thickness 0.2 mm was used in this study. And the diameter of the cylindrical cup-shaped product was 40 mm. The analytic calculation of the maximum VBHF has been compared to FEM simulations, and its effects in the prevention of cracking. Analytical Results of maximum VBHF, not much different with FEM simulation. Compared to the application of the constant blank holder force, VBHF can be quite effective for preventing the occurrence of cracking and increasing the formability of deep drawing.

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This paper explains the new design of the three wheel bike for post-stroke patients as a equipment for physical therapy. The bike can be pedaled by foot and / or by hand simultaneously. Bike frame is made of aluminum alloy pipe and consists of front and rear frame. The front frame is equipped with a steering system that can regulate the moving of two wheels of diameter of 22 ". The rear frame is equipped with a fold mechanism, shock breaker, seat and chain stay pipes for clamping the rear wheel with diameter of 22 ". The rear frame is also equipped with a mechanism of transfer speed in three levels. Bike length is 1645 mm, width 615 mm and height 1035 mm. However, after folded the bike dimension became 725 mm long, 460 mm wide and 1035 mm high. By using CATIA software the strength frame material is simulated and analyzed. The bike design is evaluated from ergonomics aspect with RULA method. The proposed design is performed into a prototype. The prototype test is conducted. The result test show, that the bike is pedaled, either by hand or foot, strong, safe and comfortable to ride. In order to evaluate the design benefit, the pedal test is also conducted in various pedal velocities by 3 post stroke patients as respondent. During 6 minutes pedaling number of rider heartbeat is measured. The result shows all the number of heartbeat is not exceeded than 120 HR. That means the bike is enough light to pedal or the patient must not give extra power to ride the bike. Moreover, during 4 weeks therapy by cycling the bike, pedal velocity each respondents is increase significantly around 26-96%, this means the muscle contraction of respondents is reduce and developed bike can be used as alternative equipment for physical therapy of post stroke patient. Because light and foldable, the bike can be moved easily and put in the trunk of a car without problem.

Drawbead are often used to control the flow of material, stress and deep drawing force in the flange area. This paper discussed the drawbead (fully, not fully and without drawbead) that combined with variations in the blank holder force against restriction of material flow and drawbead restriction force of deep drawing with palm oil lubrication. In this paper, analytical and experiments are used to predict the drawbead restraining and deep drawing force. The tin steel sheet with a thickness of 0.2 mm is used as speciment. The results obtained, that the application fully drawbead be very effective in controlling the flow of materials in the flange, as compared to not fully and without drawbead. In the beginning of the process (punch stroke < 4 mm), the magnitude of restraining force and deep drawing force can be increased. And, the magnitude of Radial Stress increases, conversely the magnitude of tangential stress decreased. This can prevent the occurrence optimum blank holder force is recommended in range 4394-8788 N. Comparisons of results between the analysis and experiments show the phenomenon is similar.