Skip header and navigation

5 records – page 1 of 1.

An Experimental and Analytical Study on the Bending Performance of CFRP-Reinforced Glulam Beams

https://research.thinkwood.com/en/permalink/catalogue2972
Year of Publication
2022
Topic
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Author
He, Minjuan
Wang, Yuxuan
Li, Zheng
Zhou, Lina
Tong, Yichang
Sun, Xiaofeng
Organization
Tongji University
University of Victoria
Editor
Tam, Lik-ho
Publisher
Frontiers
Year of Publication
2022
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Topic
Mechanical Properties
Keywords
CFRP Sheet
Four-point Bending Test
Numerical Model
Theoretical Analysis
Research Status
Complete
Series
Frontiers in Materials
Summary
The fiber-reinforced polymer is one kind of composite material made of synthetic fiber and resin, which has attracted research interests for the reinforcement of timber elements. In this study, 18 glued-laminated (glulam) beams, unreinforced or reinforced with internally embedded carbon fiber–reinforced polymer (CFRP) sheets, were tested under four-point bending loads. For the reinforced glulam beams, the influences of the strengthening ratio, the modulus of elasticity of the CFRP, and the CFRP arrangement on their bending performance were experimentally investigated. Subsequently, a finite element model developed was verified with the experimental results; furthermore, a general theoretical model considering the typical tensile failure mode was employed to predict the bending–resisting capacities of the reinforced glulam beams. It is found that the reinforced glulam beams are featured with relatively ductile bending failure, compared to the brittle tensile failure of the unreinforced ones. Besides, the compressive properties of the uppermost grain of the glulam can be fully utilized in the CFRP-reinforced beams. For the beams with a 0.040% strengthening ratio, the bending–resisting capacity and the maximum deflection can be enhanced approximately by 6.51 and 12.02%, respectively. The difference between the experimental results and the numerical results and that between the experimental results and analytical results are within 20 and 10%, respectively.
Online Access
Free
Resource Link
Less detail

Bending, Shear, and Compressive Properties of Three- and Five-Layer Cross-Laminated Timber Fabricated with Black Spruce

https://research.thinkwood.com/en/permalink/catalogue2589
Year of Publication
2020
Topic
Design and Systems
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
He, Minjuan
Sun, Xiaofeng
Li, Zheng
Feng, Wei
Publisher
SpringerOpen
Year of Publication
2020
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Design and Systems
Mechanical Properties
Keywords
Black Spruce
Panels
Bending
Thickness
Research Status
Complete
Series
Journal of Wood Science
Summary
Cross-laminated timber (CLT) is an innovative engineering wood product made by gluing layers of solid-sawn lumber at perpendicular angles. The commonly used wood species for CLT manufacturing include spruce-pine-fir (SPF), douglas fir-larch, and southern pine lumber. With the hope of broadening the wood species for CLT manufacturing, the purposes of this study include evaluating the mechanical properties of black spruce CLT and analyzing the influence of CLT thickness on its bending or shear properties. In this paper, bending, shear, and compressive tests were conducted respectively on 3-layer CLT panels with a thickness of 105 mm and on 5-layer CLT panels with a thickness of 155 mm, both of which were fabricated with No. 2-grade Canadian black spruce. Their bending or shear resisting properties as well as the failure modes were analyzed. Furthermore, comparison of mechanical properties was conducted between the black spruce CLT panels and the CLT panels fabricated with some other common wood species. Finally, for both the CLT bending panels and the CLT shear panels, their numerical models were developed and calibrated with the experimental results. For the CLT bending panels, results show that increasing the CLT thickness whilst maintaining identical span-to-thickness ratios can even slightly reduce the characteristic bending strength of the black spruce CLT. For the CLT shear panels, results show that increasing the CLT thickness whilst maintaining identical span-to-thickness ratios has little enhancement on their characteristic shear strength. For the CLT bending panels, their effective bending stiffness based on the Shear Analogy theory can be used as a more accurate prediction on their experiment-based global bending stiffness. The model of the CLT bending specimens is capable of predicting their bending properties; whereas, the model of the CLT shear specimens would underestimate their ultimate shear resisting capacity due to the absence of the rolling shear mechanism in the model, although the elastic stiffness can be predicted accurately. Overall, it is attested that the black spruce CLT can provide ideal bending or shear properties, which can be comparable to those of the CLT fabricated with other commonly used wood species. Besides, further efforts should focus on developing a numerical model that can consider the influence of the rolling shear mechanism.
Online Access
Free
Resource Link
Less detail

Performance Evaluation of Multi-Storey Cross-Laminated Timber Structures Under Different Earthquake Hazard Levels

https://research.thinkwood.com/en/permalink/catalogue1384
Year of Publication
2018
Topic
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Shear Walls
Author
Sun, Xiaofeng
He, Minjuan
Li, Zheng
Shu, Zhan
Publisher
Springer Japan
Year of Publication
2018
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Shear Walls
Topic
Design and Systems
Keywords
Equivalent Static Force Procedure
Multi-Storey
Seismic Performance
Lateral Load Resisting System
Inter-Story Drift
Pinching4 Model
Numerical Model
Probability of Non-Exceedance
Empirical Cumulative Distribution Functions
Research Status
Complete
Series
Journal of Wood Science
Summary
The inter-storey drift limitations are meaningful reference values for structural seismic performance evaluation. This paper presents an analytical investigation into the seismic performance of multi-storey cross-laminated timber (CLT) structures to obtain the drift limitations under different earthquake hazard levels reasonably. The Pinching4 model was used to simulate the nonlinear mechanical behavior of three types of connections used in CLT structures, and a numerical model was further developed to capture the lateral load-resisting properties of CLT shear walls. Moreover, three benchmark multi-storey CLT apartment buildings were designed using the Equivalent Static Force Procedure according to National Building Code of Canada (NBCC), and simplified structural models were developed for these buildings. Depending on the results from numerous time-history dynamic analyses, the empirical cumulative distribution functions (CDFs) of the maximum inter-storey drifts were constructed for the three benchmark buildings. The probability of non-exceedance (PNE) of inter-storey drift thresholds under different earthquake hazard levels was proposed and validated. It is recommended that for low-rise CLT buildings within three stories, values of 0.30%, 0.75%, and 1.40% can be considered as the drift limitations for frequent, medium, and rare seismic hazard levels, respectively. For mid-rise or high-rise buildings without three stories, 0.25%, 0.70%, and 1.30% can be considered as drift limitations.
Online Access
Free
Resource Link
Less detail

Seismic Reliability Assessment of Mid- and High-rise Post-tensioned CLT Shear Wall Structures

https://research.thinkwood.com/en/permalink/catalogue2508
Year of Publication
2020
Topic
Seismic
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Walls

Structural Design and Modelling Method for the Post-Tensioned CLT Shear Wall Structures

https://research.thinkwood.com/en/permalink/catalogue2149
Year of Publication
2019
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Walls