The Analytical Investigation on the Shear Strength of Discontinuities in Rocks Considering the Effect of Roughness and Dilatancy Angle

An analytical investigation focusing on the concrete damage progress of the PBL shear connector under the influence of various lateral pressures, employing a coupled RBSM and solid FEM model was carried out. The analytical model succeeded in simulating the test shear capacities and the failure modes adequately. The internal failure process was also clarified; the two horizontal cracks occurred near the top of the concrete dowels through the hole of the perforated steel plate, and afterward, the two vertical cracks also initiated and propagated along with the shear surface. In a low lateral pressure case, the shear strength was determined by the vertical cracks propagated along the shear surface. While as the amount of applied lateral pressure increased, the shear strength of the two vertical cracked surfaces was enhanced, and the shear strength of the PBL was characterized by the occurrence of the splitting cracks and caused the splitting failure into the side concrete blocks. Moreover, the combined effects of lateral pressure and hole diameters were also evaluated numerically, and it was found that the increase in shear strength was more in a large diameter case subjected to high lateral pressure because of the wide compressive regions generated around the concrete dowel.

Download Full-text

Compression of a Thin Plastic Mass Between Two Elastic Cylinders

Journal of Lubrication Technology ◽

10.1115/1.3554930 ◽

1969 ◽

Vol 91 (2) ◽

pp. 342-349

Author(s):

E. A. Wilson

Keyword(s):

Shear Strength ◽

Pressure Distribution ◽

Special Function ◽

Iterative Solution ◽

Analytical Investigation ◽

Circular Cylinders ◽

Plastic Mass ◽

Elastic Cylinders ◽

Thin Plastic ◽

Edge Separation

This work presents an analytical investigation of a plastic mass being compressed between the ends of two elastic circular cylinders. A special function recently tabulated by the author is used to find the deformation of the elastic cylinders due to the pressure distribution caused by the compression of the plastic mass. Based on the deformed shape of the cylinders found by the iterative solution using the special function, the author presents a simplified approximate method for finding the pressure distribution on the cylinders when given the edge separation of the cylinders and the ratio of the shear strength of the plastic mass to the modulus of elasticity in shear of the cylinders.

Download Full-text

Volume change behavior of root-permeated soils under partially saturated conditions

E3S Web of Conferences ◽

10.1051/e3sconf/202019501007 ◽

2020 ◽

Vol 195 ◽

pp. 01007

Author(s):

Anil Yildiz ◽

Frank Graf ◽

Sarah M. Springman

Keyword(s):

Shear Strength ◽

Volume Change ◽

Large Scale ◽

Horizontal Displacement ◽

Plant Functional Groups ◽

Direct Shear ◽

Dilatancy Angle ◽

Direct Shear Tests ◽

Partially Saturated ◽

Change Behavior

Vegetation, particularly roots, serves different functions in relation to increased shear strength under saturated and partially saturated conditions. Quantification of mechanical contribution of roots due to their tensile strength, and relationships of various vegetation parameters and plant-induced suction, as well as shear strength, have been widely studied. Although shear strength is directly related to the volume change characteristics of soil, dilative or contractive behaviour of root-permeated soils has not been of significant interest so far. This study investigates how volume change during shearing is related to the hydrological and mechanical characteristics of vegetated soils relevant to slope stability and shear strength of root-permeated soils under partially saturated conditions. Direct shear tests, on specimens planted with a mixture of species from different plant functional groups, were performed with an Inclinable Large-scale Direct Shear Apparatus (ILDSA). Matric suctions were monitored throughout the test with tensiometers. Vertical and horizontal displacement graphs were plotted to investigate the volume change behaviour. Maximum dilatancy angle was found to be positively correlated with plant-induced suction and net normalised stress, both of which were linked to root biomass and the root:shoot ratio. It was found that maximum dilatancy is controlled by matric suction and net normal stress.

Download Full-text

Experimental and Analytical Investigations of the Use of Groove-Epoxy Anchorage System for Shear Strengthening of RC Beams Using CFRP Laminates

Materials ◽

10.3390/ma13194350 ◽

2020 ◽

Vol 13 (19) ◽

pp. 4350 ◽

Cited By ~ 1

Author(s):

Khalid Mohamed ◽

Jamal A. Abdalla ◽

Rami A. Hawileh

Keyword(s):

Shear Strength ◽

Prediction Models ◽

Analytical Investigation ◽

Shear Capacity ◽

Coefficient Of Determination ◽

Rc Beams ◽

Shear Strengthening ◽

Cfrp Laminates ◽

Anchorage System ◽

Externally Bonded

Reinforced concrete (RC) beams strengthened in shear with carbon fiber reinforced polymer (CFRP) laminates as externally bonded reinforcement (EBR) usually fail due to debonding. This paper presents an experimental and analytical investigation on the use of groove-epoxy as an anchorage system for CFRP plates and sheets bonded on both sides of shear deficient RC beams. The aim of this study is to assess the effectiveness of using groove-epoxy in enhancing the shear capacity of RC beams. Nine rectangular RC beams were strengthened with CFRP plates and sheets with groove-epoxy anchorage systems of different groove widths and tested under four point bending. It is observed that the RC beams strengthened with the groove-epoxy anchorage system showed an increase in the shear-strength over the unstrengthened control beam up to 112 and 141% for plates and sheets, respectively. Also, the increase of shear-strength contribution of the groove-epoxy system to that of CFRP without grooves ranged between 30–190% for CFRP plates and between 40–100% for CFRP sheets. Generally, the contributions of groove-epoxy on shear-strength decreased with the increase of groove width. Moreover, shear strength prediction models, based on modifications of the ACI440.2R-17 shear model, were developed by incorporating groove factors as a modifier to the FRP shear-strength contribution. The developed models predicted the experimental shear-strength of the tested RC beams with a good level of accuracy, with an average mean absolute percent error (MAPE) = 3.31% and 6.68%, normalized mean square error (NMSE) = 0.072, 0.523, and coefficient of determination R2 = 0.964, 0.691, for plates and sheets, respectively.

Download Full-text

Analytical Investigation of Commercial Geranium Oils from Pelargonium graveolens L'Hér

Planta Medica ◽

10.1055/s-0032-1307638 ◽

2012 ◽

Vol 78 (05) ◽

Author(s):

M Wang ◽

A Chittiboyina ◽

B Avula ◽

J Zhao ◽

N Tabanca ◽

...

Keyword(s):

Analytical Investigation ◽

Pelargonium Graveolens

Download Full-text

Holding Power of Orthopaedic Screws in Metacarpal and Metatarsal Bones of Young Calves

Veterinary and Comparative Orthopaedics and Traumatology ◽

10.1055/s-0038-1633077 ◽

1992 ◽

Vol 05 (03) ◽

pp. 100-103 ◽

Cited By ~ 4

Author(s):

G. Jean ◽

J. K. Roush ◽

R. M. DeBowes ◽

E. M. Gaughan ◽

J. Kirpensteijn

Keyword(s):

Shear Strength ◽

Tensile Load ◽

Young Female ◽

Limiting Factor ◽

Holding Power ◽

Metatarsal Bones ◽

Bone Width ◽

Load To Failure ◽

Holstein Calves

SummaryThe holding power and holding power per mm bone width of 4.5 mm and 5.5 mm cortical and 6.5 mm cancellous orthopaedic screws were obtained by tensile load-to-failure studies in excised metacarpal and metatarsal bones of young female Holstein calves. Holding power and holding power per mm bone width of 6.5 mm orthopaedic screws were significantly greater than those of 4.5 and 5.5 mm orthopaedic screws in the diaphysis and metaphysis. Significant differences were not detected between holding power and holding power per mm bone width of 4.5 and 5.5 mm orthopaedic screws. The holding power was not different between metacarpi and metatarsi. The limiting factor in all tests of holding power was the shear strength of the bone. We found that 6.5 mm orthopaedic screws have the greatest holding power in the metacarpal and metatarsal bones of young calves.This study compares the holding power of 4.5 mm and 5.5 mm cortical and 6.5 mm cancellous orthopaedic screws in excised metacarpal and metatarsal bones from young female Holstein calves. We found that 6.5 mm orthopaedic screws have the greatest holding power.

Download Full-text

The Fully Softened Shear Strength of Lake Agassiz Clays

Geo-Congress 2020 ◽

10.1061/9780784482797.018 ◽

2020 ◽

Author(s):

Iván A. Contreras ◽

Jed D. Greenwood ◽

Aaron T. Grosser

Keyword(s):

Shear Strength ◽

Lake Agassiz ◽

Fully Softened Shear Strength

Download Full-text

Influence of anatomy on the adhesion performance of four wood species

Research Society and Development ◽

10.33448/rsd-v9i4.2727 ◽

2020 ◽

Vol 9 (4) ◽

pp. e31942727

Author(s):

João Gabriel Missia da Silva ◽

Pedro Nicó de Medeiros ◽

Denise Ransolin Soranso ◽

Vinicius Peixoto Tinti ◽

José Tarcísio da Silva Oliveira ◽

...

Keyword(s):

Shear Strength ◽

Specific Gravity ◽

Wood Species ◽

Tectona Grandis ◽

Glue Line ◽

Anatomical Characteristics ◽

Ray Cells ◽

Adhesion Performance ◽

Adhesion Process

The aim of this study was to evaluate the influence of anatomical characteristics on the adhesion performance of Vatairea sp., Paulownia sp., Aspidosperma populifolium and Tectona grandis wood. Specimens for anatomical, physical and mechanical analyzes were produced from tangentially oriented boards. The treatments were joint glued from pieces of the same anatomical orientation (radial and tangential), evaluated for shear strength and glue line failure. The Vatairea sp wood had the highest specific gravity (0.74 g cm-3) and the Paulownia sp (0.34 g cm-3) wood was smaller. Aspidosperma populifolium species showed the highest shear strength in the glue line in the tangential and radial faces. The anatomical variables with higher influence on the wood adhesion process were pith ray cells and especially fibers that exhibit the greatest correlation with the shear strength of the glue line.

Download Full-text