OSB Panels Research Articles

Evaluation of OSB panels using residual wood with low contents of castor oil polyurethane resin

Evaluation of OSB panels using residual wood with low contents of castor oil polyurethane resin

Evaluation of the Oriented Strand Board Properties Produced Using Tropical Wood Mixtures

The objective of this study was to evaluate the composition of OSB panels created using the Amazonian species Caryocar villosum Aubl., Erisma uncinatum Warm., and Hymenolobium excelsum Ducke. The OSB was produced using a phenol–formaldehyde adhesive at a ratio of 30:40:30 for each layer. Different mixtures of Amazonian wood and Pinus caribaea var. caribaea. were tested. Physical (water absorption and thickness swelling after 2 and 24 h of immersion in water and non-return rate in thickness) and mechanical (internal bond and parallel and perpendicular static bending) tests were performed. The OSB panels composed of wood mixtures absorbed less water after 2 and 24 h of immersion when compared to the OSB produced using pine wood. After 24 h of immersion in water, the T3 panel (40% Pinus caribaea + 40% Hymenolobium excelsum + 20% Caryocar villosum) presented the lowest absorption value. In terms of swelling in thickness at 2 h and 24 h, the panel composed of 100% pine strands showed the highest swelling value, while the T3 treatment exhibited the lowest swelling value at 2 and 24 h, as well as for the rate of non-return in thickness. Regarding mechanical properties, we observed that all panels exhibited similar resistance for both parallel and perpendicular Modulus of Rupture, as well as parallel and perpendicular Modulus of Elasticity, except for the internal bond, where T3 demonstrated the highest resistance. Additionally, some OSB panels met the requirements of the EN 300 standard for OSB panels.

FEMA P695 seismic performance evaluation of Cold-formed steel buildings with different shear wall strengths and stiffnesses

Lateral load capacity and stiffness of CFS framed OSB sheathed shear walls can be improved by increasing the number of fasteners between sheathing panel and framing members or by providing sheathing on both sides of panel. Both of these methods could be a viable option to meet high seismic demands when the number of walls is limited by architectural or other concerns. With the increasing use of CFS building systems in high seismic regions, such applications are expected to be more widespread in the future. The present study aims to investigate the seismic response of CFS framed archetype buildings utilizing OSB sheathed wall panels with different levels of stiffness and shear resistance. Nonlinear time history analyses were conducted on 28 archetype buildings and collapse performance evaluation was performed according to FEMA P695 methodology. Load-displacement hysteresis behaviors of wall panels measured in a recent experimental study were adopted to simulate the shear wall response in the numerical models. Buildings utilizing shear walls that are sheathed with OSB panels on one side with 300 mm fastener spacing possess limited overstrength and fail to satisfy the performance criteria regardless of the response modification coefficient used for design. With the use of shear walls that are constructed with 50 mm fastener spacing and single or double sided sheathing configurations, the building design is governed by drift limitation instead of strength requirement. Irregular drift profiles occur with lateral displacements localizing at the first floor when shear walls with single sided sheathing and loose fastener layout is utilized. Using shear walls with a dense fastener layout results in a uniform distribution of lateral displacements among floors.

Investigation of CFS shear walls with two-sided sheathing and dense fastener layout

Even though CFS framed shear walls have been the subject of many research, test data on walls sheathed with OSB panels on both sides using relatively small fastener spacing is scarce. The current investigation aims to fill this gap through an integrated experimental and numerical study on lateral load response of double side sheathed CFS-framed wall panels utilizing relatively small fastener spacing. The experimental investigation included cyclic tests on nine 1220x2440 mm wall panels. For the tested walls the predominant failure mode was buckling of boundary studs. The average maximum drift ratios of all tests were 3.2% and 3.0% in two loading directions. The corresponding average drift ratios at peak load capacity were 2.9% and 2.7%. The numerical part of the study included detailed modeling of wall panels using the OpenSees platform following the fastener-based and equivalent brace modeling approaches. In the fastener-based models, the nonlinear behavior of each screw between the CFS framing members and the sheathing panel was simulated by a nonlinear spring element. Material models used for these nonlinear spring elements were calibrated with the data from physical testing of connection screws. In the equivalent brace model, inelastic response of all connection screws was lumped into two nonlinear brace elements. Material models used for these brace elements were calibrated with the measured lateral load-drift data from wall panel testing. Good agreement was obtained between the numerical responses from both modeling approaches and the measured response.

Development and validation of a numerical strategy for the seismic assessment of a timber retrofitting solution for URM cavity-wall buildings

ABSTRACT This work presents the results of a numerical investigation on the effect of light timber retrofit systems on the global response of URM cavity-wall buildings. The building object of the study is a two-storey cavity-wall terraced house, retrofitted with OSB panels and timber frames. The Applied Element Method, was chosen for the numerical analyses. Numerical models, calibrated on experimental data of both retrofitted and non-retrofitted walls, were validated through the simulation of a shake-table test of a full-scale retrofitted specimen. A parametric study was then conducted to investigate the influence of different retrofit layouts on the building’s global seismic response.

Structural Analysis of Timber Gridshell Covered by OSB Panels Considering the Effect of Wind

Structural Analysis of Timber Gridshell Covered by OSB Panels Considering the Effect of Wind

Influence of the addition of Al2O3 nanoparticles and the duration of pressing on the physical properties of OSB panels

For greater durability, materials must withstand contact with water, making it difficult for biodegrading agents to attack. The present study produced and evaluated the heat transfer for two pressing times and the physical properties of OSB panels, produced with pinewood strands and Al2O3 nanoparticles addition. The nanoparticles were synthesized through the sol-gel-protein method and added to the resin in the proportion of 0.5%. During the pressing process, heat transfer and distribution in the central region of the particle mat were evaluated using a type K thermocouple. After its fabrication, the panels were characterized to evaluate density, moisture content, thickness swelling, and water absorption. The results obtained indicated that the nanoparticle addition caused a refractory effect in the central region of the mat, leading to a small reduction in the pressing temperature for the 600 s cycle. However, there was no compromise in resin cure, indicating good interaction of the panels with nanoparticles in water contact, for both pressing times. There was an improvement in the panel thickness swelling with the addition of 0.5% of Al2O3 nanoparticles, with all properties meeting the Class 1 indicators of the EN 300 (2006) standard.

Physical and Mechanical Properties of Oriented Strand Board Made from Eastern Canadian Softwood Species

This study aims to investigate the feasibility of producing OSB from softwood species used in the Eastern Canadian softwood lumber industry in the context of the overcapacity of softwood chips traditionally produced for the pulp and paper industry. Balsam fir, black spruce, and jack pine logs were used to make 15 mm thick OSB panels with a target density of 600 kg/m3. The panels were manufactured at a temperature of 210 °C during a pressing cycle of 300 s. Strands with different thicknesses were used to obtain a constant specific surface of 6.7 m2/kg for the three species. The bending modulus of the rupture and modulus of elasticity, internal bond, and thickness swelling of the OSB panels were determined and compared to the CSA standard requirements. The species significantly affected the physical and mechanical properties of OSB. The bending properties of OSB decreased with an increase in the species wood density. The internal bond strength of OSB increased with the increase in species wood density. The panels made from softwood species showed physical and mechanical properties exceeding the standard requirements, except for high thickness swelling. The combination of softwood and aspen strands significantly improved the thickness swelling of softwood-based OSB. The reduction in the surface layer density could also be explored to reduce the thickness swelling of the OSB made from the softwoods considered in this study.

Compression strength-focused properties of wood composites induced by structure

Compression strength-focused properties of wood composites induced by structure. The aim of the following study was to examine the contractual compression strength and modulus of elasticity when compressing (MOEC) of three different wood composites with various structure types: softwood (coniferous) plywood, OSB and laminated particleboard 24 mm thick. The biggest MOEC value was performed by the particleboard laminated 24 mm MOEC equalling 70.00 N/mm2. The second was found by the OSB panels, equalling 63.03 N/mm2. Last, but with MOEC value close to OSB, was softwood plywood with MOEC of 62.44 N/mm2. The lowest compression strength was observed by OSB samples, with a value of 2.75 N/mm2. The second lowest value has been performed by coniferous plywood (2.80 N/mm2). The highest compression strength occurred by the particleboard laminated 24 mm, equalling 3.31 N/mm2. Density shares and density profiles of the samples were also analysed, all of the examined composites performed U-shaped density profile The results of the study showed that there is no significant correlation between density and obtained parameters under compression. Observation of density share let the Authors conclude conversely than the results showed. It is supposed that the key factor affecting the compression performance of samples was the adhesive area and solid glue content within the composites. It is assumed that the bigger total contact surface of wood particles coated with adhesive resin, so the sum of the effective (gluing particles) surfaces of the adhesive joint is the better mechanical properties can be performed. This is why the laminated particleboard gave the best mechanical properties, while the worst were observed by the softwood plywood.

Influence of furniture exploitation on the bending strength of final mountable-dismountable corner joints

The aim of the researches presented in the paper is to show how the exploitation of furniture affect the strength of its connectors, more precisely the bending strength of the final corner dismountable joints for designed furniture – office desk. For studying this influence, 2 office desks were made (from chosen material OSB panels), joined by dismountable connectors, and also from the same material and the same type of connectors, reference test fixtures were made and their bending strength was the value of comparison. Office desks were tested according to European Standard for determining the stability of the structure (EN 527-3:2003 E) and that was simulated exploration of furniture. After that, the final corner compositions were cut off, and its bending strength was compared with the reference test fixtures strength. The research results showed that the exploiting of dismountable furniture has not a significant impact on their compositions strength.

Seismic performance factors for timber buildings with woodframe shear walls

Seismic performance factors are an engineering tool to estimate force and displacement demands on structures designed through linear methods of analysis. In Chile, the NCh433 standard provides the regulations, requirements, and factors for seismic design of several structural typologies and systems. However, when it comes to wood frame structures, previous research has found that the NCh433 provisions are highly restrictive and result in over-conservative designs. Therefore, this paper presents an experimental and numerical investigation aimed at proposing new, less restrictive seismic performance factors for wood frame buildings. Following the FEMA P-695 guidelines and a novel ground motion set for subduction zones, this research embraced: (1) testing of several full-scale specimens, (2) developing of detailed and simplified numerical models, and (3) analyzing the seismic performance of a comprehensive set of structural archetypes. 201 buildings were analyzed and results showed that changing the current NCh433 performance factors from R = 5.5 & Δmax = 0.002 to R = 6.5 & Δmax = 0.004 decreases the average collapse ratio of wood frame structures by 13.3% but keeps the collapse probability below 20% for all the archetypes under study. Besides, it improves the cost-effectiveness of the buildings and enhances their competitiveness when compared to other materials, since savings of 40.4% in nailing, 15.9% in OSB panels, and 7.3% in timber studs were found for a 5-story building case study. Further analyses showed that the buildings designed with the new factors reached the “enhanced performance objective” as defined by the ASCE 41–17 standard, guaranteeing neglectable structural and non-structural damage under highly recurring seismic events. Finally, dynamic analyses revealed that the minimum base shear requirement Cmin of the NCh433 standard is somewhat restrictive for soil classes A, B, and C, leading to conservative results compared to archetypes where the Cmin requirement did not control the structural design.

Investigation of pore size distribution by mercury intrusion porosimetry (MIP) technique applied on different OSB panels

Mercury intrusion porosimetry (MIP) is a technique used to characterize the pore size distribution and resin penetration in lignocellulosic materials, such as oriented strand board specimens (OSB), a multilayer panel utilized in structural applications. The method is based on the isostatic injection, under very high pressure, of a non-wetting fluid (mercury) into the porous material to determine parameters such as pore size distribution and percentage of porosity of the specimens. In this study, five different OSB were analyzed; they contained different wood species, resin type, and resin content. The panels manufactured with castor oil polyurethane resin showed porosity values in the range of 54.7 and 27.8%. This was a promising result compared with those obtained for panels made with phenolic resins, which are currently commercialized in Brazil.

The properties of sandwich panels made of standard wood-based panels

The properties of sandwich panels made of standard wood-based panels. The properties of sandwich panels made of standard wood-based panels were examined. Particleboards, MDF and OSB panels as well as plywood were used as internal and external layers of panels. Two types of adhesives: PUR and PVA were used to bind the layers. The physical and mechanical properties of glued sandwich panels were investigated. It was found out that OSB panels covered with plywood have the highest MOE and MOR values, and the panels with an internal layer composed of MDF have the lowest of WA and TS. It has been shown that regardless of the materials used, a panel glued with PUR achieves higher mechanical properties and the lowest WA and TS values.

INFLUENCE OF THERMAL MODIFICATION ON THE PHYSICAL AND MECHANICAL PROPERTIES OF Eucalyptus badjensis MIXED PARTICLEBOARD / OSB PANELS

The objective of this research was to evaluate the effects of thermal modifications, at different temperatures and exposure times, on the technological properties of mixed particleboard / OSB panels made out of Eucalyptus badjensis. Using the wood of Eucalyptus badjensis, Particleboard, OSB and mixed Particleboard/OSB panels (control and thermally modified) were manufactured. The mixed panels’ thermal modification was carried out under three temperatures (180ºC, 200ºC and 220ºC) and two exposure times (10 minutes and 12 minutes). For the panels’ manufacturing, 6% of phenol-formaldehyde adhesive and 1% of paraffin were employed, which was calculated based on the particles’ dry mass. The water absorption and thickness swelling properties were evaluated after 2 and 24 hours of immersion, in addition to the panels’ modulus of elasticity, modulus of rupture and internal bond. Based on the results, we were able to conclude that the thermal modification affected most of the physical properties positively. From the different exposure times studied, the most effective one was the period of 12 minutes, especially for water absorption after 2 hours, which caused a reduction of 11.27%. In turn, the most effective temperature was of 220ºC, highlighting the thickness swelling after 24 hours, which caused a swelling decrease of 23.76% in comparison with the control panels. Regarding the mechanical properties, the thermal modification, in terms of the studied exposure times and temperatures, did not affect the results of the mixed particleboard /OSB panels.

Lateral behavior of glued-laminated timber frame infilled with light-wooden-frame wall hybrid system: Experimental and numerical analysis

In this paper, experimental and numerical methodologies are used to study the lateral behaviors of glued-laminated timber (GLT) frame infilled with light-wooden-frame (LWF) wall hybrid system. Four specimens with 1:1.5 scale were designed to research the seismic performance under lateral cyclic loading, and the contribution of the LWF infill wall to the lateral structural systems, including opening size and type (door, window and without opening). The failure modes, hysteresis characteristics, lateral stiffness, energy dissipation, and load capacities of the GLT frame infilled with LWF wall systems were investigated. This paper focuses on collaborative work mechanism and lateral load sharing effect between GLT frame and infilled LWF wall and defined elastic and elastic–plastic drift ratios of the system, providing the control method for this structural hybrid system. In addition, numerical analysis methods are used to investigate the influence of wall opening size, location and type on lateral load and stiffness by 46 finite element (FE) models. The experimental results show that infilled LWF walls can provide a significant increase in the load capacities and initial lateral stiffness of GLT frame. The infilled LWF walls were very effective that it can absorb more than 70% lateral load in the initial loading stages. The numerical results show that the height and width of window & door infilled wall have a great influence on the structure lateral response, and the lateral load and stiffness increase to more than 2 times when the thickness of wall OSB panel increases from 6 mm to 16 mm.

Embalagem secundária do tipo display de OSB de resíduo de madeira-balsa (Ochroma pyramidale)

Contemporary society is becoming increasingly dependent on packaging to store products and food. The so-called secondary are produced most often with cardboard or wood. Thus, the differential of this study is the use of forest waste as a raw material to produce secondary packaging. The aim of this research was to evaluate the potential use of OSB panels of Balsa wood [Ochroma pyramidale (Cav. Ex Lam.) Urb., Malvaceae] for the production of secondary display type packaging. In this study, the physical and mechanical properties of medium density OSB panels (650 kg.m-3) produced with 13% polyurethane resin based on castor oil were analyzed in order to verify the potential of this material for use in the manufacture of packaging; a model of secondary packaging of the display type was proposed and also, a study of sensory analysis was carried out in order to identify the acceptance of this product by the users. Results obtained demonstrated the viability of structuring the secondary display type packaging for food products with OSB panels of residual Balsa wood, due to the verification of the suitability of the physical and mechanical properties of this material for use as a constituent of secondary packaging. Sensory analysis indicated acceptance of the new product by users of secondary display packaging for food.

Trapezoidal core sandwich panel produced with sugarcane bagasse

The properties of traditional particleboards are limited by their flat shape. New shapes and configurations with alternative raw materials enable strength and stiffness gains without significantly increasing weight. In this context, the present work presents an investigation of the potential use of sugarcane bagasse particles agglomerated with castor oil-based polyurethane resin to produce trapezoidal core sandwich panels for building applications. Thickness swelling was analysed based on the Brazilian standard NBR 14810 and flexure tests were performed according to the standard ASTM C393. Maximum force at failure, bending stiffness (EI), maximum moment (FbS), maximum shear stiffness (U), and core shear modulus (G) were calculated. The obtained results were compared with specifications of the standard PS-2-10 – Performance Standard for Wood-Based Structural-Use, which provides values of bending stiffness and maximum moment requirements for OSB panels according to different classes of use. The evaluated sandwich panels presented bending properties (up to 2.1×106 N-mm2/mm for EI and 1199 N-mm/mm for FbS) similar to commercial OSB panels, showing potential for sealing, structural, and flooring applications. The castor oil polyurethane resin presented acceptable efficiency as the particle binder and as an adhesive for the face-core gluing of the low density sandwich panels (0.43 MPa), meeting the minimum requirements recommended by ABNT NBR 14810:2006.

Designing a new wood-composite material made from logging waste

This study has confirmed the possibilities of using logging waste for the production of wood-composite material. The raw material for its manufacturing is the wood weaving made by flattening branches. An experimental study into the physical, mechanical, and technological properties of the wood-composite material made from the poplar branches has made it possible to determine its rational structure and the type of a binder. It has been established that ensuring the flat shape of the material requires that it should be formed of three mutually perpendicular layers. It is advisable to use urea formaldehyde resin as a binder for plates that are not exposed to the impact and static loads and are used indoors. When the material is to be applied under conditions of elevated loads and in places with high humidity, phenol-formaldehyde resin should be used. The rational pressing mode parameters have been defined: temperature, t =180 °C; pressure, p =8 MPa; holding time, τ=7 min., at which one can achieve a minimum deformation of plates after pressing. It has been proven that under these schedule parameters the holding time for the new wood-composite material to achieve the shape stabilization is also minimal; it is seven days. It has been determined that the new wood-composite material possesses the physical and mechanical properties similar to those of the OSB panels

EXPERIMENTAL RESEARCH OF THE STRESS-STRAIN STATE OF THE UNDERGROUND PIPELINE DURING ROCK SHIFTING IN THE AREAS OF ACTIVE TECTONIC FAULTS

Background In active geodynamic zones can be a change of position of the pipeline in the strength of seismic activity, landslides and clusters, and movements along faults, such as faults, reverse faults and vents, as well as the simultaneous combined effect of these movements. A local change of the position of the pipe taking place under these influences, causes additional stress from bending, and the general stress-strain condition worsens, which can lead to the destruction of pipelines and accidents. Aims and Objectives In this work, a pilot study of the deformation of the pipeline together with the ground for the analysis of stress-strain state of the pipeline and compare with the results of computer simulation. The objective of this study is to determine how much local soil movements affect the stress-strain state of the pipeline. Methods The experimental setup is a box made of OSB panels, which is filled with soil. The soil is placed in a polypropylene tube, to which is attached the load cells transmit measurements of deformation on the computer. At the bottom of the box and its lateral wall has the holes for the bars connected to the boards. These boards with the Jack alternately bring the soil in the vertical and horizontal movement. Results According to the results of the experiment, the dependences of the stresses arising in the experimental polypropylene pipe on the displacements of the soil were obtained. Using the similarity theory, these stresses were recalculated, and graphs of the dependences of stresses arising in a steel pipe, similar in parameters to that used in computer simulation, on soil displacements, were obtained. Comparison of the results of the experiment and computer simulations made earlier in the ANSYS program revealed a slight discrepancy between the results, which is explained by the inaccuracy in the selection of models for soil management. Further refinement of mathematical models is planned.

Experimental investigation of composite floor system with thin-walled steel trussed beams and partially prefabricated concrete slab

The present investigation addresses the structural behavior of steel and concrete composite floor systems, composed of thin-walled trussed members, usually adopted in the steel frame constructional technology. The floor systems of typical light-weight frame constructions are generally constituted by thin-walled beams (or open-web joist), wood-based panels (Oriented Strand Boards – OSB) and self-drilling screws connecting both materials (steel and wood). In some situations, concrete slabs are cast over the OSB panels and no shear connectors are adopted to ensure the composite action between the steel members and the concrete. In this context, one of the objectives of this work aims at presenting three new innovative solutions for shear connectors, composed of thin-walled members and attached to the top chord of the trusses by means of self-drilling screws (4.2 mm diameter). A series of experimental tests were performed in the Structures Laboratory of Federal University of Rio de Janeiro (COPPE/UFRJ), in order to provide reliable information in terms of shear strength, deformation capacity and mechanisms of collapse associated with eight push-out test specimens, according to recommendations established by Eurocode 4. Also, the performance of the referred connectors was investigated with the help of three full-scale bending tests, which revealed important characteristics regarding the structural behavior of the composite floor systems in terms of bending capacity, flexural stiffness, degree of interaction between the steel trusses and the concrete slabs, as well as strain distribution at mid-section.