scholarly journals Analysis of the Internal Mounting Forces and Strength of Newly Designed Fastener to Joints Wood and Wood-Based Panels

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7119
Author(s):  
Łukasz Krzyżaniak ◽  
Tolga Kuşkun ◽  
Ali Kasal ◽  
Jerzy Smardzewski
Keyword(s):  
Medium Density Fiberboard ◽  
Beech Wood ◽  
Experimental Studies ◽  
Bending Moment ◽  
Numerical Calculations ◽  
Medium Density ◽  
Test Results ◽  
Moment Capacity ◽  
Fagus Silvatica ◽  
3D Printed

This study aimed to numerically and experimentally analyze the effects of internal mounting forces and selected materials on the stiffness and bending moment capacity of L-type corner joints connected with novelty-designed 3D printed fasteners. The experiments were carried out using medium-density fiberboard, high-density fiberboard, beech plywood, particleboard, and beech (Fagus silvatica L.) wood. The results showed that the joints made of beech wood were characterized by the largest bending moment capacity (12.34 Nm), while the worst properties were shown by particleboard (2.18 Nm). The highest stiffness was demonstrated by plywood joints (6.56 kNm/rad), and the lowest by particleboard (0.42 kNm/rad). Experimental studies have reasonably verified the results of numerical calculations. The test results confirmed that the geometry of new fasteners promotes the mounting forces under the assembly of the joints. It was shown that the higher the density of the materials, the greater the value of the mounting forces (164 N–189 N).

scholarly journals Experimental and Analytical Study of Horizontally Curved I-Girders Subjected to Equal End Moments

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1132
Author(s):  
Jeonghyeon Lim ◽  
Young-Jong Kang ◽  
Jeonghwa Lee ◽  
Seungjun Kim ◽  
Keesei Lee
Keyword(s):  
Analytical Study ◽  
Experimental Studies ◽  
Bending Moment ◽  
Test Results ◽  
Ultimate State ◽  
Moment Capacity ◽  
Horizontally Curved ◽  
Stiffness Reduction ◽  
Interaction Curves ◽  
Good Agreement

If bending and torsional moments are applied to an I-shaped beam member, the coupling of those two forces could reduce the bending moment capacity of that member. Therefore, the interaction between bending and torsional moments is an important issue for horizontally curved members that are always simultaneously subjected to bending and torsion. In this study, the behavior of the horizontally curved steel I-beam was investigated through numerical analysis. The ultimate state of sharply curved members that showed large displacement was defined in accordance with the stiffness reduction ratio to consist of strength curves. Based on the analysis results, interaction curves were established, and a strength equation was derived. The uniform torsional moment capacity, curvature, and slenderness parameters were considered in the equation, which were the main factors that affected the ultimate strength of curved members. The curvature effect was considered individually, so that the strength of the straight or curved girder could be estimated with a unified equation. To verify the accuracy of the suggested equation, experimental studies were also conducted. Consequently, the suggested equation shows very good agreement with the test results, and is expected to provide useful information for the design of curved members.

scholarly journals Research into Corner L Separable Assemblies in Storage Furniture

2021 ◽  
Vol 72 (1) ◽  
pp. 89-98
Author(s):  
Ivica Župčić ◽  
Ivan Žulj ◽  
Igor Kamerman ◽  
Ivica Grbac ◽  
Zoran Vlaović
Keyword(s):  
Joint Strength ◽  
Medium Density Fiberboard ◽  
Bending Moment ◽  
Trade Mark ◽  
The Other ◽  
Medium Density ◽  
Research Results ◽  
Other Hand ◽  
Wear And Tear ◽  
The Impact

This research is based on the testing of the impact of the board (particleboard and medium density fiberboard (MDF)) and hardware type used to connect the sides and the bottom or top of the storage furniture on the joint strength. The hardwares of the following trade mark were used: the confirmat screw, Minifix, Maxifix, Stablofix, RV and Solo 32. Such hardwares make it possible to disassemble the furniture as well as to assemble it (when moving the furniture) without reducing joint strength when reassembling it due to wear and tear on the material (with the exception of the confirmant screw). Research results showed that assemblies with the Maxifix hardware installed in the MDF base exhibited the highest values of bending moment (the average bending moment of 85.88 Nm). On the other hand, assemblies with the Minifix hardware installed in the particleboard exhibited the lowest values of bending moment (over three times lower than the Maxifix) (the average bending moment of 24.50 Nm). Assemblies with the confirmat screw exhibited satisfactory results, although, aesthetic requirements seem to be the main problem here (the average bending moment of 40.38 Nm for the particleboard and of 64.24 Nm for the MDF).

scholarly journals A Modular Approach for Steel Reinforcing of 3D Printed Concrete—Preliminary Study

2020 ◽  
Vol 12 (10) ◽  
pp. 4062
Author(s):  
Joseph J. Assaad ◽  
Abdallah Abou Yassin ◽  
Fatima Alsakka ◽  
Farook Hamzeh
Keyword(s):  
High Strength ◽  
Modular Approach ◽  
Test Results ◽  
Moment Capacity ◽  
Structural Applications ◽  
Steel Bars ◽  
The Matrix ◽  
3D Printed ◽  
Compressive And Flexural Strengths ◽  
Transverse Steel

3D concrete printing technology has considerably progressed in terms of material proportioning and properties; however, it still suffers from the difficulty of incorporating steel reinforcement for structural applications. This paper aims at developing a modular approach capable of manufacturing 3D printed beam and column members reinforced with conventional steel bars. The cubic-shaped printed modules had 240 mm sides, possessing four holes on the corners for subsequent insertion of flexural steel and grouting operations. The transverse steel (i.e., stirrups) was manually incorporated during the printing process. The reinforced 3D printed beams were built by joining the various modules using high-strength epoxy resins. Test results showed that the compressive and flexural strengths of plain (i.e., unreinforced) 3D printed specimens are higher than traditionally cast-in-place (CIP) ones, which was mostly attributed to the injected high-strength grout that densifies the matrix and hinders the ease of crack propagation during loading. The flexural moment capacity of 3D reinforced printed beams were fairly close to the ACI 318-19 code provisions; however, about 22% lower than companion CIP members. The reduction in peak loads was attributed to the modular approach used to construct the 3D members, which might alter the fundamentals and concepts of reinforced concrete design, including the transfer and redistribution of stresses at ultimate loading conditions.

Variation of Ultimate Concrete Strain at RC Columns Subjected to Axial Loads with Bi-Directional Eccentricities

2007 ◽  
Vol 348-349 ◽  
pp. 617-620
Author(s):  
S.H. Yoo ◽  
S.W. Shin
Keyword(s):  
Bending Moment ◽  
Reinforced Concrete Beams ◽  
Minor Effect ◽  
Test Results ◽  
Axial Loads ◽  
Biaxial Bending ◽  
Moment Capacity ◽  
A Minor ◽  
Distribution Of Stress ◽  
Ultimate Concrete Strain

The distribution of stress in a nonrectangular compressed area, such as a section under a biaxial moment, is different than that of a rectangular compressed area. The properties of the compressive stress distribution of concrete have only a minor effect on the pure bending moment capacity of reinforced concrete beams, but they are important influencing factors for columns subjected to a combined axial load and a biaxial bending moment. The variation of ultimate strain of concrete according to the angle and depth of a neutral axis was investigated. Thus, the modified rectangular stress block (MRSB) model for nonrectangular compressed areas is formulated and compared to the experimental results and the existing RSB model. The MRSB method is able to provide more accurate predictions of test results for the biaxial bending moment strength than the RSB method.

The Effect of Thickness of Medium Density Fiberboard Produced of Hardwood Tree Species on their Selected Physical and Mechanical Properties

2016 ◽  
Vol 688 ◽  
pp. 115-121
Author(s):  
Liliana Valcheva ◽  
Viktor Savov
Keyword(s):  
Tree Species ◽  
Medium Density Fiberboard ◽  
Physical And Mechanical Properties ◽  
Raw Material ◽  
Medium Density ◽  
Scientific Experiments ◽  
Fagus Silvatica ◽  
Turkey Oak ◽  
Hardwood Tree ◽  
Characteristic Features

In Bulgaria, there is sufficient raw material as well as established technologies for fiberboard production of hardwood tree species. In general, MDF production from such raw-material is characterized by a number of technological difficulties mainly related to low compression ratio and smaller slenderness of fiber elements. The presented scientific experiments cover characteristic features and the effect of different thicknesses on the production of MDF from hardwood tree species – beech (Fagus silvatica L) and Turkey oak (Quercus cerris L). The experimental matrix and regime factors of hot-pressing are in correlation with thicknesses of boards. The regression models describing the effect of thicknesses on main properties of medium-density fiberboard are deduced and analyzed from the output data and the proper conclusions are made.

scholarly journals Calcium carbonate modified urea–formaldehyde resin adhesive for strength enhanced medium density fiberboard production

RSC Advances ◽  
2021 ◽  
Vol 11 (40) ◽  
pp. 25010-25017
Author(s):  
Li Lu ◽  
Yan Wang ◽  
Tianhua Li ◽  
Supeng Wang ◽  
Shoulu Yang ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Urea Formaldehyde ◽  
Medium Density Fiberboard ◽  
Urea Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Medium Density ◽  
Ionic Bond ◽  
Resin Adhesive ◽  
Uf Resin ◽  
Modified Urea

Reactions between CaCO3 and CH2O2 during polycondensation of UF resin produce Ca2+. Ionic bond complexation binds Ca2+ with UF resin. The UF resin crystalline percentage decreases from 26.86% to 22.71%. IB strength of resin bonded fiberboard increases from 0.75 to 0.94 MPa.

Experimental study of moment carrying behavior of typical Tibetan timber beam-column joints

2021 ◽  
pp. 136943322110015
Author(s):  
Ting Guo ◽  
Na Yang ◽  
Huichun Yan ◽  
Fan Bai
Keyword(s):  
Bending Moment ◽  
Structural Performance ◽  
Test Results ◽  
Timber Beam ◽  
Rotational Stiffness ◽  
Trilinear Model ◽  
Column Joint ◽  
Loading Tests ◽  
The Moment ◽  
Relationship Of

This study aimed to investigate the moment carrying behavior of typical Tibetan timber beam-column joints under monotonic vertical static load and also evaluate the influence of length ratio of Gongmu to beam (LRGB) and dowels layout on the structural performance of the joint. Six full-scale specimens were fabricated with same construction but different Gongmu length and dowels position. The moment carrying performance of beam-column joints in terms of failure mode, moment resistance, and rotational stiffness of joints were obtained via monotonic loading tests. Test results indicated that all joints are characterized by compressive failure perpendicular to grain of Ludou. Additionally, it was found that greater LRGB leads to greater initial rotational stiffness and maximum moment of the joint by an increase of restraint length for beam end; however, offsetting dowels toward column resulted smaller stiffness and ultimate bending moment of joints, particularly, offsetting Beam-Gongmu dowels toward column changed the moment-rotation curve pattern of the beam-column joint, accompanied by a hardening stiffness at last phase. Furthermore, a simplified trilinear model was proposed to represent the moment-rotation relationship of the typical Tibetan timber beam-column joint.

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