scholarly journals An Investigation of Flexural Behavior of Pure and Hybrid Wood Composite Panels Using Weibull Analyses

2021 ◽  
Vol 72 (2) ◽  
pp. 201-210
Author(s):  
Abdurrahman Karaman ◽  
H. Ersen Balcioglu
Keyword(s):  
Flexural Modulus ◽  
Medium Density Fiberboard ◽  
Wood Products ◽  
Flexural Behavior ◽  
Composite Panels ◽  
Wood Composite ◽  
Furniture Industry ◽  
Test Results ◽  
Flexural Test ◽  
Distribution Method

The production of inexpensive wood products compared to their strength is important both in terms of economy and meeting the expectations of users. For this purpose, the use of hybrid wood products is increasing in the furniture industry. With the hybridization process, relatively cheap and flimsy material is combined with a material that has a stronger structure. Thus, stronger bonded material is manufactured cheaper. In this study, the flexural behavior of pure and hybrid wood composite panels, which were prepared by applying longitudinal jointing techniques from different wood materials, was investigated. In this context, pure chipboard, pure medium density fiberboard (MDF), chipboard-east beech and MDF-east beech hybrid wood composite panels were produced. During the hybridization process, oriental beech was combined by using the self-grooving technique in three different numbers as one row, two rows, and three rows. Flexural test results were analyzed according to the Weibull distribution method. The results of the analyses showed that the hybridization process increased the flexural strength and flexural modulus of pure wood panels by up to 214 %, and 95 %, respectively.

scholarly journals Flexure Performance of Externally Bonded CFRP Plates-Strengthened Reinforced Concrete Members

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Xin Yuan ◽  
Chaoyu Zhu ◽  
Wei Zheng ◽  
Jiangbei Hu ◽  
Baijian Tang
Keyword(s):  
Failure Modes ◽  
Calculation Model ◽  
Flexural Behavior ◽  
Test Results ◽  
Flexural Test ◽  
Concrete Members ◽  
Cfrp Plate ◽  
Matlab Program ◽  
Externally Bonded ◽  
The Relationship

This paper investigates the flexural behavior of CFRP plate-strengthened concrete structures. Specimens of the CFRP plate-reinforced beam were designed and tested by the four-point flexural test. The load-deflection relationship, failure modes, and crack propagation were analyzed. The results showed that the postcracking stiffness and bearing capacity of the test beams can be improved by the additional anchoring measures for CFRP strengthening. The relationship between flexural moment and curvature was analyzed by introducing a MATLAB program. The calculation model between curvature, flexural moment, and stiffness was derived for the CFRP plate-strengthened structure. The recommended calculation model was applied in the analysis of deflection, and the theoretical values were compared with the test results.

Material-Use Trends in U.S. Furniture Manufacturing

1988 ◽  
Vol 12 (2) ◽  
pp. 102-107
Author(s):  
William G. Luppold
Keyword(s):  
Medium Density Fiberboard ◽  
The United States ◽  
Wood Products ◽  
Composite Panel ◽  
Furniture Industry ◽  
Softwood Lumber ◽  
Furniture Manufacturing ◽  
Hardwood Lumber ◽  
Panel Products ◽  
Composite Wood

Abstract Furniture manufacturers in the United States are major users of a variety of wood products. In the last two decades, traditional wood products, such as hardwood lumber, veneer, and plywood have been, in part, replaced by composite panel products, such as particleboard, hardboard, and medium-density fiberboard. This paper examines the uses of traditional and composite wood products by the wood household, upholstered household, and commercial furniture industries in descriptive and numerical terms. The analysis indicates that the substitution of composite products for traditional hardwood products has subsided in recent years in the household wood furniture industry but has continued in the commercial furniture industry. Strong growth in softwood lumber use has occurred in the household wood industry and the household upholstered furniture industry but not in the commercial furniture industry. Although hardwood lumber has been displaced by softwood-based composite panel products, greater relative decreases have occurred in hardwood veneer and veneer core plywood use because of composite panel substitution. Most recent market activities, however, indicate increased use of hardwood lumber in furniture production in the 1980s. South. J. Appl. For. 12(2):102-107.

Flexural Toughness of Sprayable Strain-Hardening Cement Composite (SHCC) for Seismic Retrofit of Non-Ductile Reinforced Concrete Frames

2013 ◽  
Vol 658 ◽  
pp. 34-37 ◽  
Author(s):  
Seung Ju Han ◽  
Hyun Do Yun
Keyword(s):  
Reinforced Concrete ◽  
Strain Hardening ◽  
Strong Influence ◽  
Volume Fraction ◽  
Cement Composite ◽  
Flexural Behavior ◽  
Test Results ◽  
Flexural Test ◽  
Concrete Frames ◽  
Flexural Toughness

This experimental study investigates the flexural behavior and toughness of sprayable strain-hardening cement composite (SHCC) developed to retrofit seismically reinforced concrete structures with non-ductile reinforcement details. Three SHCC mixtures with specified compressive strength of 50 MPa are mixed and tested. All SHCC mixes with different dosage and combination of admixtures such as superplasticizer and powder admixture were reinforced with 2.2 % polyvinyl alcohol (PVA) fibers at the volume fraction. This paper focuses on the flexural toughness based on the flexural test results for 100 x 100 x 400 mm prisms. The flexural toughness is evaluated in accordance with ASTM C 1018. The results indicated that less than 2.5 % dosage of hybrid superplasticizer and powder admixtures respectively provides excellent sprayability and flexural behavior of SHCC mixed in this study. A strong influence of hybrid superplasticizer and powder admixture on the flexural toughness of SHCC mixes was observed.

scholarly journals FLEXURAL BEHAVIOR OF FRP BARS AFTER BEING EXPOSED TO ELEVATED TEMPERATURES

2021 ◽  
Vol 18 (1) ◽  
pp. 12-19
Author(s):  
Dr. Sherif El-Gamal ◽  
Abdulrahman M. Al-Fahdi ◽  
Mohammed Meddah ◽  
Abdullah Al-Saidy ◽  
Kazi Md Abu Sohel
Keyword(s):  
Flexural Strength ◽  
Elevated Temperatures ◽  
Flexural Modulus ◽  
Flexural Behavior ◽  
Test Results ◽  
Gfrp Bars ◽  
Reinforced Polymer ◽  
Significant Strength ◽  
Glass Frp ◽  
Frp Bars

This research study investigates the flexural behavior of fiber reinforced polymer (FRP) bars after being subjected to different levels of elevated temperatures (100, 200 and 300°C). Three types of glass FRP bars (ribbed, sand coated, and helically wrapped) and one type of carbon FRP bars (sand coated) were used in this study. Two testing scenarios were used: a) testing specimens immediately after heating and b) keeping specimens to cool down before testing. Test results showed that as the temperature increased the flexural strength and modulus of the tested FRP bars decreased. At temperatures higher than the glass transition temperature (Tg), significant flexural strength and modulus losses were recorded. Smaller diameter bars showed better residual flexural strength and modulus than larger diameter bars. The immediately tested bars showed significant strength and modulus losses compared to bars tested after cooling. Different types of GFRP bars showed comparable results. However, the helically wrapped bars showed the highest flexural strength losses (37 and 60%) while the sand coated bars showed the lowest losses (29 and 39%) after exposure to 200 and 300℃, respectively. The carbon FRP bars showed residual flexural strengths comparable to those recorded for the GFRP bars; however, they showed lower residual flexural modulus after being subjected to 200 and 300℃.

Flexural and flammability evaluation of a new bio-based polyurethane foam with alumina trihydrate

2021 ◽  
pp. 146442072098659
Author(s):  
EHP Silva ◽  
GSC Souza ◽  
DB Janes ◽  
G Waldow ◽  
FCP Sales ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Polyurethane Foam ◽  
Mass Fraction ◽  
Flexural Modulus ◽  
Flexural Behavior ◽  
Test Results ◽  
Mean Values ◽  
Flammability Test ◽  
Mass Fractions ◽  
Alumina Trihydrate

Flexural and flammability evaluation of a new bio-based polyurethane foam (PUF) with alumina trihydrate (ATH) added as flame retardant were carried out. The PUF was obtained from a blend of vegetable oils. Flexural behavior of the polyurethane with different mass fractions of flame retardant (ATH) was investigated according to ASTM D790-17. Flammability tests were performed according to ASTM D3801-20 and ASTM D635-14 for the vertical and horizontal positions, respectively. The ATH addition influenced the flexural strength of the tested specimens, showing mean values for pure PUF and PUF with 50% of ATH were very close, but the highest value was obtained for PUF with 20% of ATH. Besides, the maximum strain value under flexural load was substantially reduced as the ATH mass increased, which was 11.4% for pure PUF and 3.38% for PUF with 50% of ATH. The flexural modulus increased with ATH incorporation up to 40% mass fraction. The obtained values for pure PUF, PUF with 40% of ATH and PUF with 50% of ATH specimens were 30.63 ± 1.95 MPa, 73.01 ± 2.82 MPa, and 62.16 ± 2.30 MPa, respectively. In addition, flammability test results presented better responses as the amount of ATH increased. PUF with 40% of ATH received V-2 classification, and PUF with 50% of ATH obtained HB classification. Therefore, the results for PUF with the addition of ATH show that the new bio-based material can be designed by using different mass fractions. Thus, this material becomes very useful for many types of applications, such as furniture and automobile industries, as well as sandwich structures and building constructions.

scholarly journals Flexural Strength Evaluation of Multi-Cell Composite T-Shaped Concrete-Filled Steel Tubular Beams

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2838
Author(s):  
Yanfei Shen ◽  
Yongqing Tu
Keyword(s):  
Flexural Strength ◽  
Cross Section ◽  
Bending Moment ◽  
Flexural Behavior ◽  
Unified Theory ◽  
Test Results ◽  
Infill Wall ◽  
Distribution Method ◽  
Hollow Section ◽  
Effect Factor

The multi-cell composite T-shaped concrete-filled steel tubular (MT-CFST) element is an innovative structural form. It has great potential for construction applications because of favorable advantages over traditional composite elements. The flexural strength of MT-CFST beams was investigated in this study to provide recommendations in line with existing design codes. First, formulations to evaluate the flexural strength of MT-CFST beams were derived based on the Unified Theory and plastic stress distribution method (PSDM). For the Unified Theory-based formula, a modified confinement effect factor that considers the shape of a cross-section was proposed. An experimental study on the flexural behavior of six MT-CFST beams as well as two hollow section counterparts was conducted. The influence of bending moment direction, concrete infill, wall thickness, and cross-section sizes were investigated. The accuracy of the proposed formulations was verified against the test results and numerical results from finite element modeling. The comparisons showed that the formula in line with the Unified Theory provided more accurate predictions with reasonable conservatism for the studied MT-CFST beams.

scholarly journals Development of lignocellulosic fiber reinforced cement composite panels using semi-dry technology

Cellulose ◽  
2021 ◽  
Vol 28 (6) ◽  
pp. 3631-3645
Author(s):  
K. M. Faridul Hasan ◽  
Péter György Horváth ◽  
Tibor Alpár
Keyword(s):  
Flexural Modulus ◽  
Cement Composite ◽  
Composite Panel ◽  
Bending Test ◽  
Morphological Properties ◽  
Cement Stone ◽  
Composite Panels ◽  
Internal Bonding ◽  
Dry Process ◽  
Lignocellulosic Fiber

AbstractThere is a growing interest in developing cement bonded lignocellulosic fiber (LF) composites with enhanced mechanical performances. This study assessed the possibility of developing composite panels with 12 mm thickness and around 1200 kg/m3 nominal densities from ordinary Portland cements (OPC) and mixed LFs from seven different woody plants found in Hungary. Once the mixed LFs were sieved and found fine (0–0.6 mm) and medium (0.6–0.8 mm) length fibers. The optimum ratio for LF, OPC, water glass (Na2SiO3), and cement stone was found to be 1:3.5:0.7:0.07. The semi-dry process, which is a comparatively cheaper and less labor intensive technology, was used for producing the composites. After 28 days of curing, the composite panels were characterized for mechanical, physical, thermal, and morphological properties. A scanning electron microscopy (SEM) test was conducted to observe the fiber orientation in the matrix before and after the bending test, which showed the clear presence of the fibers in the composites. The FTIR (Fourier transform infrared spectroscopy) was conducted to investigate the presence of chemical compounds of LF in the composite panels. Different physical (water absorption and thickness swelling) characteristics of the composite panels were investigated. Furthermore, mechanical properties (flexural properties and internal bonding strength) of the composite panels were also found to be satisfactory. The flexural modulus and internal bonding strengths of composite panel 2 is higher than other three boards, although the flexural strength is a little lower than composite panel 1. The thermogravimetric analysis and differential thermogravimetry also indicated better thermal stability of composite panels which could be used as potential insulation panel for buildings. Graphic abstract

scholarly journals Preliminary Qualitative Analysis and Implications of Wood Products Perception on Social Media

2020 ◽  
Vol 71 (3) ◽  
pp. 295-300
Author(s):  
Jana Šujanová ◽  
Renata Nováková ◽  
Gabriela Pavlendová ◽  
Dagmar Cagáňová ◽  
Natália Canet
Keyword(s):  
Qualitative Research ◽  
Social Networks ◽  
Social Media ◽  
Content Analysis ◽  
Civil Society ◽  
Automotive Industry ◽  
Wood Products ◽  
Furniture Industry ◽  
Current Management ◽  
University Of Technology

The article presents the results of the qualitative research of social media, managed by the Institute of the Civil Society, University of Ss. Cyril and Methodius in Trnava, in cooperation with the Slovak University of Technology in Bratislava. The research aimed to analyse different areas of the current management challenges and their perception of the selected social networks. The study concentrates on the presentation of the chosen manufacturers of the automotive industry and furniture industry on social media. The content analysis was based on the VADER (Valence Aware Dictionary and Entiment Reasoner) lexicon that was explicitly tuned to sentiments expressed in social media and QDA software.

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