Author

Konstandinos G. Raptis

National Techical University of Athens, Greece

4 articles in our journals

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Research ArticleOpen accessComparison Between Niemann’s and Finite Element Method for the Estimation of Maximum Allowable Stress of Meshing Spur Gear Teeth at Highest Point of Single Tooth ContactKonstandinos G. Raptis, Theodore N. Costopoulos, Andonios D. TsolakisPurpose of this study is the consideration of loading and contact problems encountered at rotating machine elements and especially at toothed gears. The later are some of the most commonly used mechanical components for rotary motion and power transmission. This fact proves the necessity for improved reliability and enhanced service life, which require precise and clear knowledge of the stress … …American Journal of Engineering and Applied Sciences, Vol. 5, Issue 2 · 27 Aug 2012 · 7,759 accessesView PDF Cite

Research ArticleOpen accessComparison of Maximum Gear-Tooth Operating Bending Stresses Derived from Niemann's Analytical Procedure and the Finite Element MethodAndonios D. Tsolakis, Konstandinos G. RaptisProblem statement: Main purpose of this study was to investigation toothed gear loading problems using the Finite Element Method. Approach: We used Niemann’s equations to compare maximum bending stress which was developed at critical gear-tooth flank point during gear meshing, applied for three distinct spur-gear sizes, each having different teeth number, module and power rating. Results: The results emerging after … …American Journal of Engineering and Applied Sciences, Vol. 4, Issue 3 · 18 Aug 2011 · 7,695 accessesView PDF Cite

Research ArticleOpen accessExperimental Study of Load Sharing in Roller-Bearing Contact by Caustics and PhotoelasticityKonstandinos G. Raptis, George A. Papadopoulos, Theodore N. Costopoulos, Andonios D. TsolakisProblem statement: In this study a comprehensive methodology for calculating load sharing in Roller-bearing contact was presented based on the experimental stress-optical method of caustics and Photoelasticity. Approach: The theoretical equations describing the geometry of transmitted caustic in relation to the length of the contact zone were derived and a simple mathematical set of equations correlating the maximum diameter of … …American Journal of Engineering and Applied Sciences, Vol. 4, Issue 2 · 13 Jul 2011 · 8,397 accessesView PDF Cite

Research ArticleOpen accessRating of Spur Gear Strength Using Photoelasticity and the Finite Element MethodKonstandinos G. Raptis, Theodore N. Costopoulos, Georgios A. Papadopoulos, Αndonios D. TsolakisProblem statement: Toothed gears are some of the most used machine elements for motion and power transmission between rotating shafts. This fact induces the need for improved reliability and higher endurance, which require precise and clear knowledge of the gear tooth stress field during meshing. Approach: This study considered the calculation of maximum stress at gear tooth root when the … …American Journal of Engineering and Applied Sciences, Vol. 3, Issue 1 · 31 Mar 2010 · 7,879 accessesView PDF Cite