Parameter identification for a point-supported cross laminated timber slab based on experimental and numerical modal analysis
https://link.springer.com/article/10.1007/s00107-0... [Mechanical Performance] [Journal Article] 2021
Michael Kawrza, Thomas Furtmüller, Christoph Adam, Roland Maderebner
In this paper, the dynamic properties of a point-supported cross-laminated timber slab are studied in order to determine the elastic material parameters on this basis. A detailed experimental modal analysis of the slab with dimensions 16.0 m x 11.0 m is performed, and seven modes including the natural frequencies, damping ratios and mode shape components at 651 sensor positions are identified. The found mode shapes are complex due to environmental influences that occurred during the two-day meas...

Generating 3D Finite Element Models of Boards from Computed Tomography Images
http://ltu.diva-portal.org/smash/record.jsf?pid=di... [Mechanical Performance] [Conference Paper] 2020
Huber, J. A J., Broman, O., Oja, J., Ekevad, M.
Increasingly taller and larger timber buildings have become more common. Currently, a 20-storey hotel tower made of cross-laminated timber is under construction in Skellefteå, Sweden. For construction, strength-graded timber with predictable mechanical properties is required. Commonly, strength-grading is done by heuristic methods based on indicating properties which are derived from various measurements, e.g. X-ray, laser scanning and recently also computed tomography (CT) scanning. The availab...

Experimental and numerical uncertain vibration analysis of multilayered timber structures assembled using compressed wood dowels
https://hal.univ-lorraine.fr/tel-03184623... [Vibration/Acoustic Performance] [Thesis/Dissertation] 2020
Tuan Anh Bui
This study presents an experimental and numerical investigation on the vibrational serviceability performance of novel adhesive free engineered wood products (AFEWPs), namely adhesive free laminated timber beams (AFLB) and adhesive free cross-laminated timber panels (AFCLT), assembled through thermo-mechanically compressed wood dowels (CWD). The experimental modal analyses were carried out under free-free conditions using a hammer impact. Natural frequencies, mode shapes, and damping ratio were ...

Examination of Slip Behavior in Drywall Partition Walls
https://engrxiv.org/hjg48... [Mechanical Performance] [Report] 2020
Hamed Hasani, Keri L. Ryan
Preliminary observations of Phase I testing of a subassembly of nonstructural drywall partition walls integrated with cross-laminated timber (CLT) rocking walls are reported. In this phase, the slip behavior of two straight drywall partition walls (without return walls) – one with conventional slip-track detailing and the other with telescoping detailing – was examined. These drywall partition walls were tested under a bidirectional loading protocol, which allowed for systematic evaluation of th...

Viability of Modern Timber Highway Bridges
http://www.lfpdc.lsu.edu/publications/bits/2020/20... [Alternative/Hybrid Configurations] [Report] 2019
Chris Legg
Timber is among the oldest materials used in bridge construction, and is still widely used today, especially for short and medium span bridges. However, in the second half of the 20th century, the use of timber was largely displaced by steel and concrete, and there is a current perception among many bridge designers and highway officials that timber is no longer a viable option for large-scale highway bridge projects. This perception is largely based on concerns about life span, maintenance cost...

Comparison of single-number quantities for impact sound insulation to the subjective rating of different floor configurations
https://hal.archives-ouvertes.fr/hal-03231757... [Vibration/Acoustic Performance] [Conference Paper] 2020
Dominik Kisic, Vojtech Chmelik, Jakub Benklewski, Herbert Muellner, David Knittl, Marko Horvat, Monika Rychtarikova, Kristian Jambrosic
The traditional descriptors of impact sound insulation such as Ln,w evaluate the tapping machine measurements on a floor construction by shifting the reference curve which provides a frequency-dependent weighting of the measurement. Additional single-number quantities have been developed over the years to offer a more accurate representation of the quality of impact sound insulation between dwellings. This article shows the comparison of some of the already proposed reference curves and adaptati...

Cross laminated timber wall solutions? sound reduction and impact of construction details on the airborne sound reduction
https://hal.archives-ouvertes.fr/hal-03231841... [Vibration/Acoustic Performance] [Conference Paper] 2020
Heinz Ferk, Christopher Leh, Markus Mosing, Bernd Nusser
In this paper we provide some insight on results of the ongoing national research project ?Sound.Wood.Austria? operated by Holzforschung Austria and Graz University of Technology. For a progress in the development of sound insulation prediction of wood based systems it is necessary to provide not only single number quantities for sound reduction, but also one-third octave band based quantities, determined by valid measurements. It is one of the aims of this project to provide an open access to s...

An empirical transcendental hysteresis model for structural systems with pinching and degradation
https://onlinelibrary.wiley.com/doi/full/10.1002/e... [Mechanical Performance] [Journal Article] 2021
Angelo Aloisio, Petr Sejkot, Asif Iqbal, Massimo Fragiacomo
The authors present a novel transcendental hysteresis model based on the piecewise definition of arctangent functions. The definition of the shape parameters of the arctangent functions originates from the features of the experimental hysteresis curves directly. In the first step, the authors present this models application to the experimental cyclic response of cross-laminated timber (CLT), light-timber frame (LTF) shear walls, and a steel angle bracket. Then, the response of a plywood-coupled ...

Withdrawal resistance of self-tapping screws inserted on the narrow face of cross laminated timber made from Radiata Pine
https://www.sciencedirect.com/science/article/abs/... [Connectors] [Journal Article] 2021
Xin Li, Mahmud Ashraf, Mahbube Subhani, Kazem Ghabraie, Haitao Li, Paul Kremer
With the growing global tendency towards sustainable construction techniques, the use of renewable material regains attention from the industry. Cross laminated timber (CLT), as a relatively new engineered timber product, is recognized as a viable alternative to some traditional materials for various of structures. Based on the source of original raw materials, structural responses of CLTs could vary significantly between species. In Australia, locally planted Radiata Pine (Pinus radiata D. Don)...

Quantifying the Ductility-Related Force Modification Factor for 10-Story Timber–RC Hybrid Building Using FEMA P695 Procedure and Considering the 2015 NBC Seismic Hazard
https://ascelibrary.org/doi/full/10.1061/%28ASCE%2... [Seismic Performance] [Journal Article] 2021
Solomon Tesfamariam, Konstantinos Skandalos; Katsuichiro Goda; Matiyas A. Bezabeh, Girma Bitsuamlak, Marjan Popovski
In this work, a 10-story uncoupled (10S-U) hybrid seismic force resisting system, consisting of cross-laminated timber (CLT) walls and reinforced concrete (RC) beams, is considered. Required design ductility factor Rd, in congruence with the National Building Code of Canada, was developed using FEMA P695 collapse risk procedure. Two trial Rd factors, Rd=2 and Rd=3, were first used to design the hybrid building for seismicity of Vancouver, BC, and 3D numerical models were developed in Open System...

Experimental and numerical assessment of a cross-insulated timber panel solution
https://www.sciencedirect.com/science/article/pii/... [Mechanical Performance] [Journal Article] 2021
PedroSantos, João R.Correia, Luís Godinho, A.M.P.G. Dias, Hélder Craveiro
This paper presents an experimental and numerical study about the flexural and compressive behaviour of a novel type of sandwich panel solution based on Cross-Laminated Timber (CLT). The layout of the new panel, named Cross-Insulated Timber (CIT), is similar to the one of a five-layer (CLT) panel, but the inner layer is made of polyurethane rigid foam instead of timber as in Structural Insulated Panels (SIP), aiming to rationalize the wood volume and combine it with a low-density core layer for ...

Physical, Optical, and Visual Performance of Coated Cross-Laminated Timber during Natural and Artificial Weathering
https://www.mdpi.com/2079-6412/11/2/252/xml... [Moisture/Durability] [Journal Article] 2021
Gabrielly dos Santos Bobadilha, C. Elizabeth Stokes, Katie M. Ohno, Grant Kirker, Dercilio Junior Verly Lopes. Mojgan Nejad
Cross-laminated timber (CLT) market demand is on the rise in the United States. Adequate protective measures have not been extensively studied. The objective of this study was to investigate the weathering performance of exterior wood coatings. We evaluated coated CLT sample surfaces based on visual appearance, color change (CIE*L*a*b), gloss changes, and water intrusion. From the five exterior wood coatings evaluated, only two showed adequate performance after twelve months field exposure. Base...

Love It or Leave It: What Do Millennials Really Think of Wood Products?
https://meridian.allenpress.com/fpj/article/71/2/1... [Markets] [Journal Article] 2021
Iris Montague; Kassandra Stout; Rubin Shmulsky
In the past, the wood products industry has often struggled with effectively marketing products to the public. With the increase of globalization and wood substitutions, the industry may need new ways to attract customers. Targeting younger customers who have recently joined the buyers market may be a way to increase the industrys market share and customer base. A study was conducted to understand the millennial generations (individuals born from 1980 to 2000) knowledge and perception of wood pr...

Biological Durability of Cross-Laminated Timber— The State of Things
https://meridian.allenpress.com/fpj/article/71/2/1... [Moisture/Durability] [Journal Article] 2021
Kenneth E. Udele; Jeffrey J. Morrell; Arijit Sinha
Cross laminated timber (CLT) is a mass timber product that is gaining popularity in construction within North America. CLT is made up of wood, a building material of biological origin. Therefore, these materials are at a risk of decay upon intrusion of moisture, a situation that could lead to loss of confidence in the material. Ensuring durability and optimum performance of building elements throughout their expected service life will require an understanding of the potential for decay and the p...

Experimental Modal Analysis of Appropriate Boundary Conditions for the Evaluation of Cross-Laminated Timber Panels for an In-Line Approach
https://meridian.allenpress.com/fpj/article/71/2/1... [Mechanical Performance] [Journal Article] 2021
Adam Faircloth; Loic Brancheriau; Hassan Karampour; Stephen So; Henri Bailleres; Chandan Kumar
Transverse modal analysis of timber panels is a proven effective alternative method for approximating a materials elastic constants. Specific testing configurations, such as boundary conditions (BC) and location of sensor and impact, play a critical role in the accuracy of the results obtained from the experimental assessment. This article investigates signal-specific details, such as the signal quality factor, that directly relate to the damping properties and internal friction as well as frequ...

Characterizing engineering performance of bamboo-wood composite cross-laminated timber made from bamboo mat-curtain panel and hem-fir lumber
https://www.sciencedirect.com/science/article/abs/... [Raw Materials] [Journal Article] 2021
Hao Li, Brad Jianhe Wang, Libin Wang, Peixing Wei, Yang Wei, Pengzhan Wang
During the global industrialization process of manufacturing cross-laminated timber (CLT), attempts have been made to use local wood species. For areas rich in bamboo resources but relatively short in timber resources, the use of bamboo- and wood-based composites to manufacture composite CLT (CCLT) has great potential. In the present work, two new types of 3-ply CCLT panel structures constituting bamboo mat-curtain panel and hem-fir lumber were investigated. In the major and minor strength direc...

Time-dependent performance in post-tensioned CLT shear walls under varied environment
https://www.taylorfrancis.com/chapters/edit/10.120... [Moisture/Durability] [Book/Book Section] 2020
Minjuan He, Xiuzhi Zheng, Zheng Li, Qi Luo, Xiling Yang
The seismic performance of post-tensioned cross-laminated timber (CLT) shear walls during long-term service is dependent on the time-varying prestressing force. The prestressing force in the steel strand may change over time because of creep and environmental deformation of timber. In this study, three different post-tensioned CLT shear walls were monitored to investigate the prestressing force variation under uncontrolled environment. The environmental temperature, relative humidity, timber moi...

Vibration performance of cross-laminated timber (CLT) floor under multi-person load
https://www.taylorfrancis.com/chapters/edit/10.120... [Vibration/Acoustic Performance] [Book/Book Section] 2020
Haoyu Huang, Chang Wang, Xiaoqi Lin, Wen-Shao Chang
The vibration of cross laminated timber (CLT) floor is closely related to the human-induced load. However, at present, the research on human-induced vibration of CLT floor is mostly limited to single person activity. In this study, the influence of multi-person load on the dynamic performance of CLT floor was studied. The open source software framework seismic engineering simulation open software (OPEN-SEES) was used to simulate the dynamic performance of CLT floor. A new model was developed to ...

Design of a base isolated timber building in the historical center of an high seismic hazard area of Italy
https://www.taylorfrancis.com/chapters/edit/10.120... [Seismic Performance] [Book/Book Section] 2020
A.V. Bergami, C. Casadei, M. Follesa, L. Franciosini, C. Nuti, B. Briseghella, D. Vassallo
This paper deals with the design of an innovative school building under construction in the historical center of Ariano Irpino (Italy). The building has been designed to be integrated into the historical Town, with very peculiar and innovative structural aspects. The very characteristic heritage location, with small access roads and typical historical buildings, and the site topography, at the top of the hill characterized by sloping sides and high retaining structures, with high seismic hazard,...

Local 3D fibre orientation for tensile strength prediction of European beech timber
https://www.sciencedirect.com/science/article/abs/... [Mechanical Performance] [Journal Article] 2021
Andreas Raisa, Martin Bacher, Ani Khaloian-Sarnaghi, Monika Zeilhofer, Andriy Kovryga, Francesco Fontanini, Torben Hilmers, Maximilian Westermayr, Martin Jacobs, Hans Pretzsch, Jan-Willemvan de Kuilen
In central Europe forests, the share of European beech (Fagus sylvatica L.) trees has been increased in the last decades. Machine strength grading of hardwood is challenging due to a lack of knowledge about strength predictors. However, high strength classes are needed for the utilization as glued and cross laminated timber. We used the information of an industrial scanner on fiber orientations, developed a 3D cluster value (SOG3D,150,max) for strength assessment and combined the parameter with ...