Protective rigid fiber-reinforced polyurethane foam composite boards: Sound absorption, drop-weight impact and mechanical properties

This paper presents experimental results regarding the efficiency of using acoustic panels made with fiber-reinforced alkali-activated slag foam concrete containing lightweight recycled aggregates produced by using Petrit-T (tunnel kiln slag). In the first stage, 72 acoustic panels with dimension 500 × 500 × 35 mm were cast and prepared. The mechanical properties of the panels were then assessed in terms of their compressive and flexural strengths. Moreover, the durability properties of acoustic panels were studied using harsh conditions (freeze/thaw and carbonation tests). The efficiency of the lightweight panels was also assessed in terms of thermal properties. In the second stage, 50 acoustic panels were used to cover the floor area in a reverberation room. The acoustic absorption in diffuse field conditions was measured, and the interrupted random noise source method was used to record the sound pressure decay rate over time. Moreover, the acoustic properties of the panels were separately assessed by impedance tubes and airflow resistivity measurements. The recorded results from these two sound absorption evaluations were compared. Additionally, a comparative study was presented on the results of impedance tube measurements to compare the influence of casting volumes (large and small scales) on the sound absorption of the acoustic panels. In the last stage, a comparative study was implemented to clarify the effects of harsh conditions on the sound absorption of the acoustic panels. The results showed that casting scale had great impacts on the mechanical and physical properties. Additionally, it was revealed that harsh conditions improved the sound properties of acoustic panels due to their effects on the porous structure of materials.

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Drop-weight impact testing for the study of energy absorption in automobile crash boxes made of composite material

Proceedings of the Institution of Mechanical Engineers Part L Journal of Materials Design and Applications ◽

10.1177/1464420720952813 ◽

2020 ◽

pp. 146442072095281

Author(s):

N Nasir Hussain ◽

Srinivasa Prakash Regalla ◽

Yendluri V Daseswara Rao ◽

Tatacipta Dirgantara ◽

Leonardo Gunawan ◽

...

Keyword(s):

Glass Fiber ◽

Energy Absorption ◽

Impact Testing ◽

Fiber Reinforced ◽

Glass Fiber Reinforced Plastic ◽

Fiber Reinforced Plastic ◽

Drop Weight ◽

Glass Fiber Reinforced ◽

Reinforced Plastic ◽

Weight Impact

There is an ever-increasing demand in the automotive sector to continuously improve the performance and reduce cost through weight reduction in the structure of the vehicle. In the present scenario, it is also necessary to meet the standards set by crash safety regulating authorities in various parts of the world. In automobiles, the crash box is placed in the anterior region to absorb the impact energy in the event of an accident. Glass fiber reinforced plastic crash boxes have a high strength-to-weight ratio and also are good in energy absorption, particularly useful in this scenario. In this paper, the effectiveness of different triggers in combination with various geometries is investigated for Glass fiber reinforced plastic crash boxes using drop-weight impact testing. A trigger is a geometric irregularity introduced in the crash box design to alter the energy as well as force levels by modifying the deformation mode under loading. Comparison of change in force level, absorption of impact energy, specific energy absorption values was performed for composite crash boxes made of various types of cross-sectional geometries along with multiple patterns of triggers. Force versus displacement (F–D) curves are drawn for all the cases of the glass fiber reinforced plastic crash boxes to understand the behavior of each combination formed with various types of geometries and triggers, under impact loading. Strength-to-weight ratio was considered as the deciding factor for the comparisons to know the best and worst cases of the crash boxes made of different cross-sections along with various trigger types. This study provides detailed insights into the drop-weight impact testing procedure including the preparation of specimens, setting up the drop-weight impact test, preparation of specimen clamps, safety precautions involved, data acquisition from the test and its processing.

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Effect of Kenaf Fiber on Morphology and Mechanical Properties of Rigid Polyurethane Foam Composite

Materials Science Forum ◽

10.4028/www.scientific.net/msf.888.188 ◽

2017 ◽

Vol 888 ◽

pp. 188-192 ◽

Cited By ~ 2

Author(s):

Nur Suhaili Mohd Soberi ◽

Rozyanty Rahman ◽

Firuz Zainuddin

Keyword(s):

Mechanical Properties ◽

Polyurethane Foam ◽

Cell Shape ◽

Kenaf Fiber ◽

Kenaf Core ◽

Foam Composite ◽

The Matrix ◽

Sem Micrograph ◽

Core Fiber ◽

Irregular Cell

In this work polyurethane foam composites were prepared by using kenaf core fiber as filler at different percentages. Polyurethane foam acts as the matrix and was prepared by using palm oil based polyol and isocyanate with ratio of 1:1.1. From the results obtained, composites filled with kenaf core fiber showed lower mechanical properties i.e modulus and compression strength, up to 85% decrease. However the addition of kenaf core fiber decreases the rise time of the polyurethane foam composites. SEM micrograph analysis showed the evidence of irregular cell shape with the presence of kenaf core fiber. The percentage of kenaf core fiber plays crucial role in determining the composites properties.

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Experimental Study on Drop-Weight Impact Response of Basalt Fiber Aluminum Laminates (BFMLs)

Advances in Materials Science and Engineering ◽

10.1155/2018/1478951 ◽

2018 ◽

Vol 2018 ◽

pp. 1-13

Author(s):

Dongliang Zhang ◽

Xiaoyan Zhang ◽

Yunrong Luo ◽

Qingyuan Wang

Keyword(s):

Energy Absorption ◽

Volume Fraction ◽

Basalt Fiber ◽

Fiber Reinforced Polymer ◽

Aluminum Sheet ◽

Fiber Reinforced ◽

Reinforced Polymer ◽

Drop Weight ◽

Weight Impact ◽

Basalt Fiber Reinforced Polymer

The basalt fiber-reinforced polymer (epoxy resin), which has even better mechanical properties than glass fiber-reinforced polymer, is a good choice for making FML (fiber-metal laminate) composite. Herein, drop-weight impact tests of basalt fiber-based FMLs (called BFMLs) were conducted in the INSTON 9520HV testing machine to investigate the low-velocity impact properties of BFMLs. The specimens were of two diameters. And the impactors had two sizes of nose, dropping from different heights. The load-deflection behavior of aluminum sheet, BFRP (basalt fiber-reinforced polymer) panel, and BFML plate and their energy dissipation patterns during impact perforation were obtained. The test results showed that aluminum alloy sheet and BFMLs had no strain rate effect, while BFRP did. It was also concluded that the behavior of the thick BFML plate was clearly affected by debonding between aluminum sheet and BFRP panel, while the behavior of the thin BFML plate was controlled by membrane force. In failure analysis, it was found that the deformation and breakage of BFRP are the main contributions to energy absorption of BFMLs which counts for more than 75%. The energy absorbed by the aluminum sheet through plastic deformation and petaling is about 20%, while the energy absorbed in debonding can be ignored. In addition, with the help of ABAQUS simulation, it was found that decreasing the value of MVF (metal volume fraction) can increase the specific energy absorption of BFMLs, but the ductility of BFMLs may decrease.

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