www.tjprc.org SCOPUS Indexed Journal editor@tjprc.org DAMPING IMPROVEMENT OF A CANTILEVER BEAM USING TWO PATCHES OF FLUIDIC FLEXIBLE MATRIX COMPOSITE TUBES SHIREN O. MUHAMMAD & NAZHAD A. HUSSAIN Department of Mechanical and Mechatronics Engineering, Salahaddin University - Erbil, Iraq ABSTRACT Fluidic Flexible Matrix Composite (F 2 MC) tubes are promising fiber reinforced tubes, they can passively provide damping and vibration absorption. This study focuses on analyzing F 2 MC tube’s response to add damping to cantilever structures. A novel cantilever beam vibration absorber encompassing different models of a patch of F²MC tubes has been examined. A new mathematical model was performed for a system that composed of two short patches instead of one, bonded in various positions on the beam. The study extracted transfer functions of reduced mathematical models of the beam into MATLAB ® software. It focused on the amplitude and frequency of resonance of mode shapes. The results demonstrated that F 2 MC tubes that composed of two layers of composite fiber reinforced layers from inside reduced the first mode amplitude by 12.12dB. Whereas, increasing the number of patches reduced the first resonance amplitude by 11.12dB. Through comparing the integration of two patches with one patch, single tube is more powerful than a couple of tubes, it gains a reduction of 14dB in First mode shape amplitude. Depending on the above results the study utilized a reduction in both amplitude and frequency of resonance by 20.7dB and 53Hz in FRF plot, respectively. KEYWORDS: Vibration Absorbers, F 2 MC Tubes, Fiber Reinforced Layers, Frequency Response Function, Mathematical Model & Cantilever Beam Received: Jun 18, 2019; Accepted: Jul 12, 2019; Published: Sep 11, 2019; Paper Id.: IJMPERDOCT201925 1. INTRODUCTION Fluidic Flexible Matrix Composite (F 2 MC) tubes are a new class of tight, compromise smart and light weight fiber reinforced composite laminates with high degree of anisotropy. The fibers oriented as ±α° with respect to the longitudinal axis, the layers enclosed a working fluid. The fluid flow is controlled by valve and accumulator. These devices are new candidates of vibration reducers and they can passively provide damping, vibration absorption, and vibration isolation of the structures that directly connected with them. The first idea of using FMC tubes was found by (Philen, Ying, Bakis, Wang, & Rahn 2006). The authors took advantage from the FMC tube’s fiber reinforcement configuration and bulk modulus of working fluid in closed valve scenario to obtain a variable stiffness adaptive smart structure that can be used as energy absorbers. In another study, Ying et al. investigated the capacity of F 2 MC tubes for self-governing structural tailoring (Ying Shan et al., 2009). They developed an analytical model to study the axial stiffness of a single F 2 MC tube. Some mechanical properties had been tailored, such as: inner liner modulus of elasticity, F 2 MC tube’s thickness and working fluid’s bulk modulus. As a result, a flexible FMC tube with a wider range of tailor ability had been obtained. Also, (Philen, 2010) investigated on an active valve control for tuning the modulus of F 2 MC tubes. They derived a simple model for finding the dynamic response of combined system including composite tubes, control valves, and fluid flow rate inside them through experimental tests, with Original Article International Journal of Mechanical and Production Engineering Research and Development (IJMPERD) ISSN (P): 2249–6890; ISSN (E): 2249–8001 Vol. 9, Issue 5, Oct 2019, 287–304 © TJPRC Pvt. Ltd