Pub Date : 1900-01-01DOI: 10.3844/AJASSP.2017.34.52
R. Aversa, R. Petrescu, A. Apicella, F. Petrescu, J. Calautit, M. Mirsayar, R. Bucinell, Filippo Berto, B. Akash
First time the corresponding author has studied these problems of motors in V, in the framework of some contracts made with the research collective of UPB and "Autobuzul" plant, in years 1980-1986. In the first phase, have been studied the vibrations and noises of an engine in V, their transmissibility from the engine to the chassis and the cab driver and the possibility of reducing vibration (of the engine or the submitted) by their insulation. Reducing the vibration transmitted, has taken place in various ways, but their level at the driver's seat and the passengers was still too large, much more than the allowed limits international. The vibrations were still more than the allowed limits, while in a similar engine Otto or diesel in a straight line, they were in line with the normal limits, until at last it was decided to change the type of the engine. The idea of the paper's authors was: "It can be synthesized one motor in V only by changing the alpha angle value (the constructive angle of a V engine)". By this method it is possible to change the kinematics of this motor and in the same time its dynamic work. Generally the constructive angle of an engine in V was calculated in function of the number of cylinders and by the engineering condition to achieve an ignition distributed uniformly to all cylinders. This paper try to solve the principal problem of any motor in V (noise and vibration) having in view that one motor in V is more dynamic, more powerful and has a higher yield than any other heat engine. The solution was found and it is very simple to be implemented. It needs only an angle value change. It's about the constructive angle, alpha. Calculations to demonstrate this fact and all the theory are very difficult and heavy. But the final result is very simple.
{"title":"Something About the V Engines Design","authors":"R. Aversa, R. Petrescu, A. Apicella, F. Petrescu, J. Calautit, M. Mirsayar, R. Bucinell, Filippo Berto, B. Akash","doi":"10.3844/AJASSP.2017.34.52","DOIUrl":"https://doi.org/10.3844/AJASSP.2017.34.52","url":null,"abstract":"First time the corresponding author has studied these problems of motors in V, in the framework of some contracts made with the research collective of UPB and \"Autobuzul\" plant, in years 1980-1986. In the first phase, have been studied the vibrations and noises of an engine in V, their transmissibility from the engine to the chassis and the cab driver and the possibility of reducing vibration (of the engine or the submitted) by their insulation. Reducing the vibration transmitted, has taken place in various ways, but their level at the driver's seat and the passengers was still too large, much more than the allowed limits international. The vibrations were still more than the allowed limits, while in a similar engine Otto or diesel in a straight line, they were in line with the normal limits, until at last it was decided to change the type of the engine. The idea of the paper's authors was: \"It can be synthesized one motor in V only by changing the alpha angle value (the constructive angle of a V engine)\". By this method it is possible to change the kinematics of this motor and in the same time its dynamic work. Generally the constructive angle of an engine in V was calculated in function of the number of cylinders and by the engineering condition to achieve an ignition distributed uniformly to all cylinders. This paper try to solve the principal problem of any motor in V (noise and vibration) having in view that one motor in V is more dynamic, more powerful and has a higher yield than any other heat engine. The solution was found and it is very simple to be implemented. It needs only an angle value change. It's about the constructive angle, alpha. Calculations to demonstrate this fact and all the theory are very difficult and heavy. But the final result is very simple.","PeriodicalId":174359,"journal":{"name":"EngRN: Industrial & Manufacturing Engineering","volume":"488 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124261586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Alcalá, Jan Ocenasek, Ph.D., Javier Varillas, Ph.D., Jaafar El-Awady, Ph.D., Jeffrey Wheeler, Ph.D., Johann Michler, Ph.D.
Plastic deformation in crystalline materials consists of an ensemble of collective dislocation glide processes, which lead to strain burst emissions in micro-scale samples. To unravel the combined role of crystalline structure, sample size and temperature on these processes, we performed a comprehensive set of strict displacement-controlled micropillar compression experiments in conjunction with large-scale molecular dynamics and physics-based discrete dislocation dynamics simulations. The results indicate that plastic strain bursts consist of numerous individual dislocation glide events, which span over minuscule time intervals. The size distributions of these events follow a power-law function which bifurcates from an incipient slip regime of uncorrelated glide (spanning ≈ 2.5 decades of slip sizes) to a large avalanche domain of collective glide (spanning ≈ 4 decades of emission probability) at a critical slip magnitude sc. This critical slip size characterizes the transition between bulk-like and localized plasticity. In face-centered cubic (FCC) metals, sc is essentially governed by the interplay between dislocation annihilation, cross-slip and junction formation processes developing as a function of microcrystal size and stacking fault width in Al, Ni and Cu. Dislocation starvation then rules the avalanche statistics in smaller microcrystals. In body-centered cubic (BCC) metals, sc evaluates the combined role of temperature and the applied stress level upon the glide of the sluggish screw dislocations via cross-kinking mechanisms. Different sc values result in BCC Ta and W due to the distinctive thermal and stress-dependent activation of cross-kinking. These FCC and BCC dislocation glide mechanisms determine the evolution from self-organized to stress-tuned avalanching processes.
{"title":"Statistics and Mechanisms of Intermittent Plasticity in FCC and BCC Microcrystals","authors":"J. Alcalá, Jan Ocenasek, Ph.D., Javier Varillas, Ph.D., Jaafar El-Awady, Ph.D., Jeffrey Wheeler, Ph.D., Johann Michler, Ph.D.","doi":"10.2139/ssrn.3458114","DOIUrl":"https://doi.org/10.2139/ssrn.3458114","url":null,"abstract":"Plastic deformation in crystalline materials consists of an ensemble of collective dislocation glide processes, which lead to strain burst emissions in micro-scale samples. To unravel the combined role of crystalline structure, sample size and temperature on these processes, we performed a comprehensive set of strict displacement-controlled micropillar compression experiments in conjunction with large-scale molecular dynamics and physics-based discrete dislocation dynamics simulations. The results indicate that plastic strain bursts consist of numerous individual dislocation glide events, which span over minuscule time intervals. The size distributions of these events follow a power-law function which bifurcates from an incipient slip regime of uncorrelated glide (spanning ≈ 2.5 decades of slip sizes) to a large avalanche domain of collective glide (spanning ≈ 4 decades of emission probability) at a critical slip magnitude <i>s<sub>c</sub></i>. This critical slip size characterizes the transition between bulk-like and localized plasticity. In face-centered cubic (FCC) metals, <i>s<sub>c</sub></i> is essentially governed by the interplay between dislocation annihilation, cross-slip and junction formation processes developing as a function of microcrystal size and stacking fault width in Al, Ni and Cu. Dislocation starvation then rules the avalanche statistics in smaller microcrystals. In body-centered cubic (BCC) metals, <i>s<sub>c</sub></i> evaluates the combined role of temperature and the applied stress level upon the glide of the sluggish screw dislocations <i>via</i> cross-kinking mechanisms. Different <i>s<sub>c</sub></i> values result in BCC Ta and W due to the distinctive thermal and stress-dependent activation of cross-kinking. These FCC and BCC dislocation glide mechanisms determine the evolution from self-organized to stress-tuned avalanching processes.","PeriodicalId":174359,"journal":{"name":"EngRN: Industrial & Manufacturing Engineering","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131788500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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