scholarly journals Substitutive Press-Bolster and Press-Ram Models for the Virtual Estimation of Stamping-Tool Cambering

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 279
Author(s):  
Farshad Abbasi ◽  
Alex Sarasua ◽  
Javier Trinidad ◽  
Nagore Otegi ◽  
Eneko Saenz de Argandoña ◽  
...  

Today’s stamping simulations are realized by ignoring the elastic deformation of the press and tooling system through the assumption of a rigid behavior and a perfect press stroke. However, in reality, the press and tool components deform elastically and are one of the major error sources for the final adjustment and blue-spotting of the dies. In order to tackle this issue, a new approach is proposed in this study that substitutes the press stiffness by means of a substitutive model composed of cost-effective shell and beam elements. The substitute model was calibrated using full-scale measurements, in which a 20,000 kN trial press was experimentally characterized by measuring its deformation under static loads. To examine the robustness of the substitute model, a medium-size tool and a large-size tool were simulated together with the substitutive model. To this end, a B-pillar tool was re-machined based on the substitute-model results and a new cambering procedure was proposed and validated throughout the blue-painting procedure. The newly developed substitute model was able to replicate the global stiffness of the press with a high accuracy and affordable calculation time. The implementation of the findings can aid toolmakers in eliminating most of the reworking and home-line trials.

2020 ◽  
Vol 5 (2) ◽  
pp. 93-100
Author(s):  
R.O. Kuku ◽  
O.A. Adefuye ◽  
O.L. Fadipe ◽  
G.I. Adebowale ◽  
O.M. Delogan

The need for new designs of Groundnut oil expeller is based on the cost and efficiency of the machine especially for the usage in small and medium size industries. It has to be cost effective and light weight to accommodate such demands. The existing Groundnut Oil Expellers in the market are too big and too expensive for these small medium size businesses to invest on. Other limitations are its maintenances aspect as well as its operations. Therefore, series of survey and research have been done to identify the needs and base on that, the Final Design and Specifications were synthesized. The Groundnut Oil Expeller is a screw type machine, which presses groundnut through a barrel-like cavity. Raw material (groundnut) enters one side of the press and by product (cake) exit the other side. The machine uses friction and continuous pressure from the screw drives to move and compress the groundnut. The oil seeps through small openings that do not allow groundnut fibre solids to pass through. Afterward, the pressed groundnuts are formed into a hardened cake, which is removed from the machine. This machine will satisfy the demand for the small and medium size industries because of its design, functionality and price. The measurements of the performance also being analyze by calculating the design efficiency.


2019 ◽  
Vol 2019 (4) ◽  
pp. 7-22
Author(s):  
Georges Bridel ◽  
Zdobyslaw Goraj ◽  
Lukasz Kiszkowiak ◽  
Jean-Georges Brévot ◽  
Jean-Pierre Devaux ◽  
...  

Abstract Advanced jet training still relies on old concepts and solutions that are no longer efficient when considering the current and forthcoming changes in air combat. The cost of those old solutions to develop and maintain combat pilot skills are important, adding even more constraints to the training limitations. The requirement of having a trainer aircraft able to perform also light combat aircraft operational mission is adding unnecessary complexity and cost without any real operational advantages to air combat mission training. Thanks to emerging technologies, the JANUS project will study the feasibility of a brand-new concept of agile manoeuvrable training aircraft and an integrated training system, able to provide a live, virtual and constructive environment. The JANUS concept is based on a lightweight, low-cost, high energy aircraft associated to a ground based Integrated Training System providing simulated and emulated signals, simulated and real opponents, combined with real-time feedback on pilot’s physiological characteristics: traditionally embedded sensors are replaced with emulated signals, simulated opponents are proposed to the pilot, enabling out of sight engagement. JANUS is also providing new cost effective and more realistic solutions for “Red air aircraft” missions, organised in so-called “Aggressor Squadrons”.


Alloy Digest ◽  
1982 ◽  
Vol 31 (12) ◽  

Abstract AISI Type S2 is a water-hardening tool steel with extreme toughness and resistance to shock loading. Even at a hardness of Rockwell C 59-60, it will bend before it breaks. When hardened in medium-size and large-size pieces, it acquires a hard case and a tough core. Sizes under 3/4-inch (19mm) diameter will water harden to the center. The extreme toughness of Type S2 makes it suitable for use in many applications where no other tool steel will hold up. Its many uses include chisels, rivet busters, spike mauls, screw drivers, punches and sledges. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on forming, heat treating, machining, and joining. Filing Code: TS-408. Producer or source: Tool steel mills.


Author(s):  
Georgios Ermidis ◽  
Rasmus C. Ellegard ◽  
Vincenzo Rago ◽  
Morten B. Randers ◽  
Peter Krustrup ◽  
...  

The purpose of this study was to quantify the exercise intensity and technical involvement of U9 boys’ and girls’ team handball during different game formats, and the differences between genders. Locomotor activity (total distance, distance in speed zones, accelerations, and decelerations), heart rate (HR), and technical involvement (shots, goals, and duels) metrics were collected during various 15 min game formats from a total of 57 Danish U9 players (37 boys and 20 girls). Game formats were a small size pitch (20 × 13 m) with 3 vs 3 players and offensive goalkeepers (S3 + 1) and 4 vs 4 players (S4), a medium size pitch (25.8 × 20 m) with 4 vs 4 (M4) and 5 vs 5 (M5) players, and a large size pitch (40 × 20 m) with 5 vs 5 (L5) players. Boys and girls covered a higher total distance (TD) of high-speed running (HSR) and sprinting during L5 games compared to all other game formats (p < 0.05; ES = (−0.9 to −2.1), (−1.4 to −2.8), and (−0.9 to −1.3) respectively). Players covered the highest amount of sprinting distance in L5 games compared to all other game formats (p < 0.01; ES = 0.8 to 1.4). In all the game formats, players spent from 3.04 to 5.96 min in 180–200 bpm and 0.03 min to 0.85 min in >200 bpm of the total 15 min. In addition, both genders had more shots in S3 + 1 than M5 (p < 0.01; ES = 1.0 (0.4;1.7)) and L5 (p < 0.01; ES = 1.1 (0.6;2.2)). Team handball matches have high heart rates, total distances covered, and high-intensity running distances for U9 boys and girls irrespective of the game format. Locomotor demands appeared to be even higher when playing on larger pitches, whereas the smaller pitch size and fewer players led to elevated technical involvement.


Author(s):  
E. Telegina ◽  
M. Tadzhiev

According to judgemental forecasts, in the next few years the revolutionary changes in the energy complex both in the USA and in the world in general are hardly possible, considering the enormous inertia of the energetic system and high expenses coming from the infrastructure supersession, even in case of cost-effective alternatives to the existing energy commodities. At the same time, the sharpening of energy security problems resulting from the growth of a global demand on energy products leads to perceprion of necessity for a new approach to forming the global energy market, and to development of new stability and reliability strategies maintenance for assured supplies of energy products. In recent years, the USA as the biggest consumer of energy resources in the world worked out a new national strategy of energy security provision. Its main targets are: meeting the requirements of the American economy of its own resources, lowering the import-dependence level, high use of innovation technologies, significant increase of investments in alternative energy sources, as well as of resource-and energy-saving.


eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Thomas Zhihao Luo ◽  
Adrian Gopnik Bondy ◽  
Diksha Gupta ◽  
Verity Alexander Elliott ◽  
Charles D Kopec ◽  
...  

The use of Neuropixels probes for chronic neural recordings is in its infancy and initial studies leave questions about long-term stability and probe reusability unaddressed. Here, we demonstrate a new approach for chronic Neuropixels recordings over a period of months in freely moving rats. Our approach allows multiple probes per rat and multiple cycles of probe reuse. We found that hundreds of units could be recorded for multiple months, but that yields depended systematically on anatomical position. Explanted probes displayed a small increase in noise compared to unimplanted probes, but this was insufficient to impair future single-unit recordings. We conclude that cost-effective, multi-region, and multi-probe Neuropixels recordings can be carried out with high yields over multiple months in rats or other similarly sized animals. Our methods and observations may facilitate the standardization of chronic recording from Neuropixels probes in freely moving animals.


2016 ◽  
Vol 1140 ◽  
pp. 361-368
Author(s):  
Stefan Hilscher ◽  
Richard Krimm ◽  
Bernd Arno Behrens

Presses with mechanical linkages based on levers between motor and ram (path-linked presses) tend to oscillate due to inertial forces as a consequence of the drive parts motion.In this publication a new approach for a mass-balancing system is presented. This system allows to generate the optimal compensation forces needed to counteract the inertial forces by means of four linear motors. The control signals for the linear motors are specified by an evolutionary optimization algorithm, which operates on the base of measured accelerations of the press frame. The control signals of the linear motors are created in a way that the machines oscillations are reduced to a minimum. This way the presented mass-balancing system adapts itself automatically to varying conditions during the operation of the machine, such as a tool change or a varying stroke rate.In particular, the present publication provides the results of the conceptual design and the virtual testing of this approach, which has been mainly carried out with the help of multiple-body simulations.


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