Experimental Investigation on Dynamic Characteristics of Polypropylene Honeycomb Sandwich Structures under the Influences of Different Temperatures

2014 ◽  
Vol 606 ◽  
pp. 153-157
Author(s):  
P. Nagasankar ◽  
S. Balasivanandha Prabu ◽  
Velmurugan Ramachandran ◽  
R. Paskaramoorthy

The dynamic characteristics of the Polypropylene honeycomb (PPHC) sandwich composites have been investigated under various temperatures (30°,35°,40°,45°,50°,55°,60°, 65°,70°,75° and 80°C) and different orientations (0° and 90°) of the glass fibers in the composites. Since the thermal properties of the constituent materials (glass fiber, epoxy resin and PPHC core) of the PPHC sandwich composites are different and the in-plane effect of the composites varies with the two different orientations (0° and 90°) of the fibers, the variation of the loss factor under the various temperatures are also different for these orientations. A two stage layup technique has been used to fabricate the sandwich composite specimens. Impulse technique associated with the half power bandwidth method, has been used to evaluate the natural frequency and damping values of the sandwich composite under different temperatures.

2020 ◽  
pp. 002199832096484
Author(s):  
Tohid Dastan ◽  
Aida Safian ◽  
Mohammad Sheikhzadeh

As a way to save petroleum resources, considerable efforts were made in the last three decades to develop green composites. Green composites are a category of composite materials in which at least one phase (reinforcement or matrix) is made from renewable resources. An attempt was made to present a simple fabrication process to produce hollow integrally woven sandwich composites. In addition, the potential of jute fibers to be utilized as piles in the core of an integrally woven sandwich composite was assessed and compared to the counterparts made using glass fibers. The crashworthiness performances of integrally woven sandwich composite samples considering the effect of relative density, pile material and the presence of polyurethane foam were investigated through performing quasi-static flat-wise compression tests. Based on the findings, the foam-filled integrally woven sandwich composites exhibited stable compression load-displacement response and better energy absorption properties over pure foam, which make them appropriate for automobile interior components. Moreover, a computational cost-efficient finite element modeling was presented and subsequently validated with experimental results.


2006 ◽  
Vol 306-308 ◽  
pp. 739-744 ◽  
Author(s):  
Xiao Dong Cui ◽  
Tao Zeng ◽  
Dai Ning Fang

The impact response and energy absorbing characteristics of laminated, foam sandwich and honeycomb sandwich composites under ballistic impact have been studied in this investigation. An improved model is proposed in this paper to predict the ballistic property of the laminated composites. In this model, the material structures related to fiber lamination angles are designed in terms of their anti-impacting energy absorption capability. The ballistic limit speed and energy absorption per unit thickness of the three composites under different conditions are calculated. It is shown that honeycomb sandwich composite has the best ballistic resistance capability and energy absorption property among the three composites.


2011 ◽  
Vol 291-294 ◽  
pp. 1025-1038
Author(s):  
Qiang Liu ◽  
Zheng Ming Huang

This paper investigates nonlinear responses of honeycomb sandwich composite under externally applied loads theoretically and experimentally. In the experimental work, honeycomb sandwich composites made of an aluminum honeycomb core and glass fiber reinforced polymer (FRP) laminate surfaces were loaded under in-plane tension and out-of plane bending up to failure. Stress-strain curves or load deflection plot together with elastic moduli and ultimate strengths were obtained. An energy approach was used to establish a nonlinear constitutive relationship for the honeycomb sandwich composites. Making use of the superimposition ability of the strain energies of all of the walls of the RVE, a nonlinear constitutive relationship for the honeycomb core was obtained. The thus obtained relationship was incorporated with a laminate theory and the bridging model to analyze nonlinear responses of the honeycomb core and FRP surface sandwich composites up to failure. The composite failure was detected micromechanically, i.e., based on the failure status of its constituent aluminum core, reinforcing fiber, polymer matrix, and adhesion layer. Stiffness discount was applied respectively to the failed composing element. The predicted nonlinear stress-strain curves under tension and load-deflection relationship under three-point bending were compared with the experimental measurements. Favorable correlations have been obtained.


2018 ◽  
Vol 32 (9) ◽  
pp. 1204-1223
Author(s):  
M Idriss ◽  
A El Mahi

The article presents the results of experimental and finite element analyses of the flexural vibration behavior sandwich composite with different debonding ratios. Sandwich composite consists of two thin skins composed of E-glass fiber and epoxy resin bonded to lightweight and weaker core material of PVC foams. Experimental tests using the impulse technique were performed on the sandwich constituents and sandwich composites with different debonding lengths. The modal dynamic characteristics of sandwich composite were measured and discussed for each debonding ratio. A finite element modeling was used to determine the natural frequencies, modal shapes, and stress and strain fields for each element of sandwich composites for each debonding ratio. The modal strain energy approach was used to determine the contribution of energies dissipated of the core and the skins in the total dissipated energy and the global damping of the different sandwich composites. The results obtained by this approach are compared with those obtained experimentally.


2014 ◽  
Vol 893 ◽  
pp. 245-249
Author(s):  
P. Nagasankar ◽  
S. Balasivanandha Prabu ◽  
Velmurugan Ramachandran ◽  
R. Paskaramoorthy

The dynamic characteristics of fiber reinforced polymer skins with the alternate arrangement of continuous and chopped fibers on the polypropylene honeycomb core are investigated. It is envisaged that the damping could be improved by splitting the length of fiber into different short lengths so that more energy can be dissipated. The dynamic characteristics of FRP specimens with different forms of fibers were studied. The fibers were considered in the following five groups:, all continuous fibers, alternate arrangement of continuous and two chopped fibers, the same with three chopped fibers, four chopped fibers, and the five chopped fibers in. The natural frequencies and damping loss factors were evaluated by using the impulse technique with the half power band width method. The results revealed that for a given fiber volume fraction the damping could be improved by reducing the length of fibers.


2012 ◽  
Vol 184-185 ◽  
pp. 1167-1170
Author(s):  
Guang Yu Du ◽  
Zhen Tan ◽  
Kun Liu ◽  
Hao Chai ◽  
De Chun Ba

In this paper TiN coating was prepared on stainless steel substrate using arc ion plating technique. The coating samples’ phases, surface morphology, micro-determination chemical composition, loss factor and damping ratio were tested. The phases of TiN coating were determined by X-ray diffraction (XRD) technique. The surface morphology and chemical composition of the TiN coating were analyzed by scanning electron microscope (SEM) and Energy Dispersive Spectrometer (EDS), respectively. The damping performance of the samples was measured by hammering activation according half power bandwidth method. The loss factor or damping ratio of samples were obtained according frequency response curve. The results showed that damping performance of samples was considerably improved by TiN coatings.


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