Author

Theodore N. Costopoulos

National Techical University of Athens, Greece

5 articles in our journals

Articles where this person is an author, newest first. People are matched by their name as printed (no ORCID iD is recorded for them), not by name alone; search the name as text to find namesakes too.

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 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

Research ArticleOpen accessOn the Use of Rolling Element Bearings' Models in Precision MaintenanceIoannis S. Zotos, Theodore N. CostopoulosProblem statement: Rolling element bearings form a very important part of machinery. The increasing demands on their continuous reliable operation under diverse environments make maintenance a very important step towards the efficient use of them. To this end, precision maintenance is a very useful practice, since it deals not only with finding a possible fault of a machine, but also … …American Journal of Engineering and Applied Sciences, Vol. 2, Issue 2 · 30 Jun 2009 · 7,413 accessesView PDF Cite

Research ArticleOpen accessA Study on the Increase of Numerical Stability and Accuracy of the Transfer Matrix MethodIoannis S. Zotos, Theodore N. CostopoulosProblem Statement: The transfer matrix method is a very useful tool for the static and dynamic analysis of structures. There are a number of issues though that worsens the numerical stability and the accuracy of this method. Approach: This study proposed a simple technique that can be used to handle these numerical difficulties and overcome the problems they give. Its … …Journal of Mathematics and Statistics, Vol. 4, Issue 4 · 31 Dec 2008 · 7,030 accessesView PDF Cite