Investigation of the Effects of Polyurethane Foam Reinforcement Thickness on Modal Properties of Sandwich Beams

Öz

In this study, the effects of polyurethane foam (PUF) reinforcement thickness on modal properties (natural frequency, mode shape and damping ratio) of sandwich beams were investigated. For this purpose, two types of PUF reinforced beams were used. The one of these was reinforced onto one surface of aluminum metal face sheet and the other was reinforced between two aluminum metal face sheets were produced. Each type was prepared in different PUF thicknesses from 10 mm to 50 mm. The modal properties were obtained by using experimental modal analysis (EMA) method for both types.

Anahtar Kelimeler

• Modal analysis,Polyurethane Foam,Sandwich Beam

Poliüretan Köpük Takviye Kalınlığının Sandviç Kirişlerin Modal Özellikleri Üzerine Etkilerinin İncelenmesi

Öz

Bu çalışmada, poliüretan köpük (PUF) takviye kalınlığının sandviç kirişlerin modal özelliklerine (doğal frekans, mod şekli ve sönüm) etkileri araştırılmıştır. Bu amaçla, iki tip PUF takviyeli kiriş, biri alüminyum meta tabakasının bir yüzeyi üzerine ve diğeri iki alüminyum metal tabaka arasına takviye edilmiştir. Her tip 10 mm'den 50 mm'ye kadar farklı PUF kalınlıklarında hazırlanmıştır. Modal özellikler, her iki tip için deneysel modal analiz (EMA) yöntemi kullanılarak elde edilmiştir

Anahtar Kelimeler

• Doğal Frekans,Poliüretan Köpük,Sandviç Kiriş

Kaynakça

1. [1] Sen M. Investigation thickness effects on dynamic system characteristics of plates reinforced with pu foam, master of science. Firat University, Mechanical Engineering, Elazig. 2016. [2] Sen M., Cakar O. Experimental modal analysis of a polyurethane sandwich panel, international conference on engineering and natural science (ICENS). Sarajevo, Bosnia. 2016. [3] Davies P., Singh R., Bajaj A. K. Estimation of the dynamical properties of polyurethane foam through use of Prony series. Journal of Sound and Vibration. 264, 1005-1043., 2003. [4] Lodhia B.B., Esat I.I. Vibration simulation of systems incorporating linear viscoelastic mounts using Pronyseries formulation, American Society of Mechanical Engineers, Petroleum Division. 81, 171-176, FLEXChip Signal Processor (MC68175/D), Motorola, 1996. [5] Ferry J.D. Performance of TCP congestion control with rate feedback: TCP/ABR and rate adaptive TCP/IP, Viscoelastic Properties of Polymers, Wiley, New York, USA, 1970. Karnik, M. Eng. thesis, Indian Institute of Science, Bangalore, India, Jan. 1999. [6] Gandhi F., Chopra I. A. time-domain non-linear viscoelastic damper model, Smart Materials and Structures, 5, 517–528, 1996.Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specification, IEEE Std. 802.11, 1997. [7] Havaldar S. S., Sharma R. S., Experimental investigation of dynamic characteristics of multilayer PU foam sandwich panels, Journal of Minerals and Materials Characterization and Engineering. 1, 201-206, 2013. [8] Barbieri N., Barbieri R., Winikes L. C., Parameters estimation of sandwich beam model with rigid polyurethane foam core, Mechanical Systems and Signal Processing: 24, 406-415.2010. [9] Neves P. C., Rodrigues J. D., Fernandes A. A. Modal analysis of a composite sandwich panel used in the structure of an hybrid bus, 18th International Conference on Composite Structures, Lisbon, Portugal, 15-18 June 2015. [10] Sen M., Cakar O., Sanliturk I. H., Investigation thickness effects of polyurethane foam core used in sandwich structures via modal analysis method, Kuala Lumpur/ Malaysia, 12th International Conference on Latest Trends in Engineering and Technology (ICLTET 2017), 2017. [11] Sen M., Cakar O., Experimental modal analysis of a polyurethane sandwich panel, International Conference on Engineering and Natural Science (ICENS), Sarajevo, Bosnia. 2016.