Moiré Supported Stress Distribution Study On Gears [aplicação Da Técnica De Moiré No Estudo Da Distribuição De Cargas Em Engrenagens]

Gears are widely employed in farm machinery transmission units. However, the severe environment imposed to the machine operation generates special problems associated to maintenance, as well as to the expected time life. Machinery which works on field are exposed to excessive dust, moisture, heat, chemicals, uneven mechanical loading and quite frequently the manufacturer recommendations are not adequate or not even available. Based on that, the proposal of new methods for strain and stress distribution analysis on gears under different working conditions is considered necessary. This research paper introduces the application of moiré methods to replace the popular strain gage technique. The proposed method is included in the photomechanical techniques and is considered of easy as well as of low cost application. The moiré family of methods is based on the projection of optical grids onto the object under analysis, generating optical fringes which displace as the object is deformed under mechanical loads. In this research work the tests were carried under different working conditions, as (1) non lubricated clean gears, (2) clean and lubricated, (3) lubricated and contaminated with soil. The comparison of these three situations indicated the influence of soil contamination as well as of the lubrication. The conclusion emphasizes the application of the proposed method to gear transmission design as well as to maintenance.443157164Cohen, E.A., Stress Concentration Investigationof holes in Ortotropical Sheet appying the Reflection Fotoelasticity Method (2001), p. 103. , PhD. Thesis. University of São Paulo, São Paulo, BrazilDal Fabbro, I.M., Gazzola, J., Rabelo, G.F., Rodrigues, S., Mechanical Behavior of Sugarcane Stalks Under Diametrical Compression Assisted by a Moiré Technique (2005) Proceedings of ITAFE'05, pp. 234-236. , ADANA, TurkeyDoyle, J.F., (2008) Hybrid Methods, Springer handbook of Solid Mechanics, , Ed. Sharpe, New YorkGazzola, J., Affonso, E.A., Dal Fabbro, I.M., Application of the Moiré Optical Technique in Determining the Deformation Map on Bodies under Axial Loading (2013) Journal Sinergia, São Paulo, pp. 211-216Gazzola, J., Dal Fabbro, I.M., Soriano, J., Silva, M.V.G., Rodrigues, S., Photomechanical analysis of wooden testing bodies under flexural loading (2012) World Academy of Science, Engineering and Technology, 70, pp. 396-401Gazzola, J., Application of the Moiré Technique in the Stress Distribution Study on Log Bundles Reduced Models and Cut Wooden Pieces (2011), p. 151. , Master Degree Dissertation. Faculty of Agricultural Engineering, State University of Campinas, SP. BrazilGomes, S.T., Calibration of the Moiré Technique Applied to Mechanical Prototypes Profile (2009) Science and Agrotechnique, 33 (2). , http://dx.doi.org/10.1590/S1413-70542009000200033, Lavras Mar./Apr.2009Koda, F., Study of Contac Fatigue in Straight Teeths Cylindrical Gears (2009), Master Degree Thesis, Technological University of Paraná - UTFPRKuninari, F., Dal Fabbro, I.M., Lino, A.C.L., Almeida, C., Moiré aided soil-tractor tire contact area and contact volume determination (2008) Journal of Agricultural Machinery Science, 4 (1), pp. 39-43Lei, Z., Yun, H., Yun, D., Kang, Y., Numerical analysis of phase-stepping interferometric photoelasticity for plane stress separation (2007) Optics and Laser in Engineering, 45 (1), pp. 77-82Lino, A.C.L., Application of the Phase Displacement Projection Moiré Method in Generating Plant Organs Digital Models (2008), p. 92. , PhD Thesis, Faculty of Agricultural Engineering, State University of Campinas, SP, BrazilMaugis, D., (2000) Contact, adesion and rupture in elastic solids, , New York: Springler-VerlagMyiake, Experimental Stress Analysis applying Digital Processing of Reflection Fotoelastical Method (2004) Brazilian Society of Computational and Applied Mathematic, Ilha Solteira, 1, pp. 1427-1431Rodrigues, L.E.M., Specialization Course on Total Productive Maintenace (2008), http://www.ebah.com.br/content/ABAAAe5ocAJ/falhas-engrenagensSantos, A.A., Notes on Machine Elements 2 (2002), http://www.fem.unicamp.br/~lafer/em618/,pdf/Apostila%20Engrenagens%204.pdf, Campinas, marchSciammarella, C.A., The moiré method - A review (1982) Experimental Mechanics, 44 (8), pp. 418-433Spinelli, H.A., Silva, F.A., Application of Photoelasticity on Structural Analysis of a Riveted Joint for Aeronautical Application (2003) Anais. Guaratinguetá