Longitudinal shear in wood beams: a design method

1977 ◽  
Vol 4 (3) ◽  
pp. 363-370 ◽  
Author(s):  
Ricardo O. Foschi ◽  
J. David Barrett
Keyword(s):  
Shear Strength ◽  
Brittle Fracture ◽  
Design Method ◽  
Longitudinal Shear ◽  
Douglas Fir ◽  
Wood Beams

The results of a study on longitudinal shear strength of Douglas fir, based on Weibull's theory of brittle fracture, are implemented in a design method. Design formulae are given and required parameters are calculated for several common configurations of beams and loadings. A method for extending the results to other species is proposed.

Shear strength of spruce glued—laminated timber beams

1985 ◽  
Vol 12 (3) ◽  
pp. 661-672 ◽  
Author(s):  
F. J. Keenan ◽  
J. Kryla ◽  
B. Kyokong
Keyword(s):  
Shear Strength ◽  
Cross Sections ◽  
Weibull Model ◽  
Longitudinal Shear ◽  
Douglas Fir ◽  
Published Data ◽  
Cross Sectional ◽  
Characteristic Value ◽  
Glued Laminated Timber ◽  
Timber Beams

The effect of size on longitudinal shear strength has been well established for Douglas-fir glued–laminated (glulam) timber beams. The present study examined whether this phenomenon exists in glulam beams made of spruce. The experiment consisted of three projects in which beams of various sizes were tested under concentrated mid-span load. The project A beams had clear spruce webs and white elm flanges with cross-sectional dimensions varying from 25 × 25 mm to 75 × 75 mm. The project B beams had spruce glulam webs with Douglas-fir flanges; cross sections ranged from 20 × 100 mm to 90 × 200 mm. In project C, three groups of 10 replications of commercially representative sizes of glulam beams were made from stiffness-rated spruce–pine–fir lumber. The beam cross sections were 76 × 200 mm, 76 × 400 mm, and 127 × 400 mm.The results indicated that depth, width, and shear plane had significant effects on the longitudinal shear strength of the beams in project A. Depth, width, and shear span of the small glulam beams in project B also had highly significant effects on shear strength. However, no effects of depth and width on the shear strength of glulam beams in project C were found. Regression analysis showed no dependence of shear strength on sheared volume for the beams of all three projects. The three-parameter Weibull model also failed to predict the near-minimum shear strength of spruce glulam beams. The results suggested that the lower-bound shear strength of spruce glulam beams is a constant (regardless of beam volume) and could be used as a single characteristic value for glulam design in shear. Further review of published data indicates that this may also be the case for Douglas-fir glulam but with a lower characteristic value than for spruce.

Longitudinal shear strength of Douglas-fir

1976 ◽  
Vol 3 (2) ◽  
pp. 198-208 ◽  
Author(s):  
Ricardo O. Foschi ◽  
J. D. Barrett
Keyword(s):  
Shear Strength ◽  
Longitudinal Shear ◽  
Douglas Fir ◽  
Shear Stresses ◽  
Loading Conditions ◽  
Theoretical Predictions ◽  
The Difference ◽  
American Society ◽  
Shear Block

Weibull's theory of brittle fracture is applied to the determination of strength of Douglas-fir wood in longitudinal shear. Ultimate stresses, at a given survival probability, are derived for beams under different loading conditions. The theory allows an explanation for the difference in shear strength between beams and the standard American Society for Testing Materials shear block, as well as for the dependence of shear strength upon beam size. The theory is verified by comparing theoretical predictions and test results on Griplam nailed connections loaded parallel to the grain and shear tests on torque tubes. Very good agreement is shown. Finally, allowable shear stresses for beams under different loading conditions are derived.

Longitudinal shear strength prediction for steel-concrete composite slabs with additional reinforcement bars

2020 ◽  
Vol 166 ◽  
pp. 105908 ◽  
Author(s):  
Luiz Gustavo Fernandes Grossi ◽  
Carol Ferreira Rezende Santos ◽  
Maximiliano Malite
Keyword(s):  
Shear Strength ◽  
Longitudinal Shear ◽  
Strength Prediction ◽  
Composite Slabs

Effect of grain angle on shear strength of Douglas-fir wood

Holzforschung ◽  
2012 ◽  
Vol 66 (5) ◽  
pp. 655-658 ◽  
Author(s):  
Rakesh Gupta ◽  
Arijit Sinha
Keyword(s):  
Shear Strength ◽  
Root Mean Square ◽  
Failure Mode ◽  
Shear Plane ◽  
Douglas Fir ◽  
Mean Square ◽  
Rolling Shear ◽  
Grain Angle ◽  
Shear Block ◽  
The Relationship

Abstract The effect of grain angle (GA) on shear strength of Douglas-fir has been evaluated. Shear block specimens with a GA varying from 0 to 90° was loaded in the shear plane, resulting in failure mode transitioning from parallel to grain shear to rolling shear. As expected, shear strength decreased as the GA increased from 0° to 90°. A root-mean-square equation was found to be suitable to predict the relationship between GA and shear strength. Traditional Hankinson formula and the Tsai-Wu criteria were less effective with this regard.

Perpendicular-to-Grain Strength of Douglas-Fir

1975 ◽  
Vol 2 (1) ◽  
pp. 50-57 ◽  
Author(s):  
J. D. Barrett ◽  
R. O. Foschi ◽  
S. P. Fox
Keyword(s):  
Experimental Data ◽  
Brittle Fracture ◽  
Survival Probability ◽  
Douglas Fir ◽  
Curved Beams ◽  
Allowable Stresses ◽  
Laminated Material

Weibull's theory of brittle fracture is applied to the determination of strength of Douglas-fir wood in tension perpendicular to the grain. Results from tests on blocks of glued-laminated material uniformly stressed in tension are used to derive ultimate stresses, at a given survival probability, for pitched-tapered beams, curved beams, and griplam nail connections. The results of the theory are shown to be in agreement with experimental data. Allowable stresses are derived for blocks, pitched-tapered beams, curved beams, and the particular nailed connection studied.

scholarly journals The improved design method of shear strength of reinforced concrete beams without transverse reinforcement

2017 ◽  
Vol 12 (2) ◽  
pp. 39-45 ◽  
Author(s):  
Pavlo Vegera ◽  
Rostyslav Vashkevych ◽  
Roman Khmil ◽  
Zinoviy Blikharskyy
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Design Method ◽  
Variable Parameter ◽  
Reinforced Concrete Beams ◽  
Shear Span ◽  
Depth Ratio ◽  
Effective Depth ◽  
Improved Design

Abstract In this article, results of experimental testing of reinforced concrete beams without transverse shear reinforcement are given. Three prototypes for improved testing methods were tested. The testing variable parameter was the shear span to the effective depth ratio. In the result of the tests we noticed that bearing capacity of RC beams is increased with the decreasing shear span to the effective depth ratio. The design method according to current codes was applied to test samples and it showed a significant discrepancy results. Than we proposed the improved design method using the adjusted value of shear strength of concrete CRd,c. The results obtained by the improved design method showed satisfactory reproducibility.

scholarly journals Flexural and Shear Performance of Prestressed Composite Slabs with Inverted Multi-Ribs

2019 ◽  
Vol 9 (22) ◽  
pp. 4946 ◽  
Author(s):  
Sun-Jin Han ◽  
Jae-Hoon Jeong ◽  
Hyo-Eun Joo ◽  
Seung-Ho Choi ◽  
Seokdong Choi ◽  
...  
Keyword(s):  
Shear Strength ◽  
Design Method ◽  
Precast Concrete ◽  
Flexural Behavior ◽  
Structural Performance ◽  
Design Codes ◽  
Analysis Model ◽  
Non Linear ◽  
Shear Performance ◽  
Flexural Analysis

Half precast concrete slabs with inverted multi-ribs (Joint Advanced Slab, JAS), which enhance composite performance between slabs by introducing shear keys at connections between the slabs and improve structural performance by placing prestressing tendons and truss-type shear reinforcements, have recently been developed and applied in many construction fields. In this study, flexural and shear tests were performed to verify the structural performance of JAS members. Towards this end, two flexural specimens and four shear specimens were fabricated, and the presence of cast-in-place concrete and the location of the critical section were set as the main test variables. In addition, the flexural and shear performance of the JAS was quantitatively evaluated using a non-linear flexural analysis model and current structural design codes. Evaluation results confirmed that the flexural behavior of the JAS was almost similar to the behavior simulated through the non-linear flexural analysis model, and the shear performance of the JAS can also be estimated appropriately by using the shear strength equations presented in the current design codes. For the JAS with cast-in-place concrete, however, the shear strength estimation results differed significantly depending on the way that the shear contributions of the precast concrete unit and cast-in-place concrete were calculated. Based on the analysis results, this study proposed a design method that can reasonably estimate the shear strength of the composite JAS.

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