Effect of Timber Grain Orientation on Bonded-In Rod Connection Systems

2012 ◽  
Vol 517 ◽  
pp. 695-704
Author(s):  
Hannah Pearson ◽  
Mark Evernden ◽  
Richard Harris
Keyword(s):  
Failure Criterion ◽  
Material Properties ◽  
Grain Orientation ◽  
Maximum Stress ◽  
Tensile Behavior ◽  
Plate Structures ◽  
Stress Theory ◽  
Pull Out ◽  
Connection System ◽  
Timber Products

Presented in this paper are the results of practical tests to determine some key material properties of engineered timber, in particular glulam. The results are discussed and compared with three known failure criterion, Hankinsons formula, The Tsai-Wu criterion and Maximum stress theory to determine if they are appropriate models for predicting the properties of glulam. The properties considered have been chosen with respect to a connection system for use in folded plate structures utilizing embedded rods. This paper considers the effect of the timber grain angle on the compression, tensile and steel dowel rod pull-out strengths. The test data shows that Hankinson and Tsai-Wu are both good models to predict both the compression and tensile behavior of engineered timber products at non-tangential angles, whereas maximum stress theory had less correlation and over predicts the results and would not be recommended for use in engineered timber materials.

A new static failure criterion for ductile materials

1997 ◽  
Vol 32 (5) ◽  
pp. 345-350 ◽  
Author(s):  
S-J Wang ◽  
M W Dixon
Keyword(s):  
Experimental Data ◽  
Failure Criterion ◽  
Material Properties ◽  
Maximum Shear Stress ◽  
Stress Theory ◽  
Ductile Materials ◽  
Special Cases ◽  
Von Mises ◽  
New Criterion ◽  
Static Failure

A new static failure criterion is proposed with a function of the stress state as well as the material properties (the ratio of ty /Sy), which is based on the experimentally determined ratio of Ty to Sy and includes the maximum shear stress theory and the von Mises-Hencky theory as special cases. The new criterion has a great potential to fit the experimental data and appears to fit better the very limited experimental data found in the open literature.

THE EFFECT OF LAMINATION SCHEME AND ANGLE VARIATIONS TO THE DISPLACEMENTS AND FAILURE BEHAVIOUR OF COMPOSITE LAMINATE

2015 ◽  
Vol 76 (11) ◽  
Author(s):  
Azizul Hakim Samsudin ◽  
Jamaluddin Mahmud
Keyword(s):  
Fiber Orientation ◽  
Composite Laminates ◽  
Finite Element Modelling ◽  
Composite Laminate ◽  
Maximum Stress ◽  
Failure Load ◽  
Failure Criteria ◽  
Stress Theory ◽  
Failure Behaviour ◽  
Failure Index

This paper aims to investigate the effect of lamination scheme and angle variations to the displacements and failure behaviour of composite laminate. Finite element modelling and analysis of symmetric, anti-symmetric and angle-ply Graphite/ Epoxy laminate with various angles of fiber orientation subjected to uniaxial tension are performed. Maximum Stress Theory and Tsai-Wu Failure Criteria are employed to determine the failure load (failure index = 1). Prior to that, convergence analysis and numerical validation are carried out. Displacements and failure behaviour of the composite laminates (symmetric, anti-symmetric and angle ply) are analysed. The failure curves (FPF and LPF) for both theories (Maximum Stress Theory and Tsai-Wu) are plotted and found to be very close to each other. Therefore, it can be concluded that the current study is useful and significant to the displacements and failure behaviour of composite laminate.

Numerical Prediction of Rock Fracturing During the Process of Excavation

2012 ◽  
pp. 225-237 ◽  
Author(s):  
Zhangtao Zhou ◽  
Zheming Zhu ◽  
XinXing Jin ◽  
Hao Tang
Keyword(s):  
Equation Of State ◽  
Numerical Model ◽  
Failure Criterion ◽  
Material Properties ◽  
Igneous Rock ◽  
Surrounding Rock ◽  
Rock Blasting ◽  
Rock Fracturing ◽  
Fracturing Process ◽  
Blasting Excavation

During the process of excavation, blasting can induce cracking inside the surrounding rock. Considering the effects of material properties and loading conditions, a rock blasting excavation model with two successive excavation steps was developed through the use of AUTODYN code. Four kinds of equation of state (EOS), linear, shock, JWL, and compaction were applied to the materials employed in this numerical model. A modified principal stress failure criterion was applied to determining material statuses, and TNT explosive and a relatively homogeneous igneous rock, diorite, were used in this numerical model. By using this numerical model, rock fracturing process during blasting excavation was simulated, and rock fracturing process during two successive excavations is presented.

Prediction of Traction in Sliding EHD Contacts

1976 ◽  
Vol 98 (3) ◽  
pp. 362-365 ◽  
Author(s):  
R. Kunz ◽  
W. O. Winer
Keyword(s):  
Shear Stress ◽  
Film Thickness ◽  
Surface Temperature ◽  
Material Properties ◽  
Rheological Model ◽  
Normal Load ◽  
Point Contact ◽  
Temperature Data ◽  
Stress Theory ◽  
Surface Temperature Data

An existing shear stress theory and lubricant rheological model were studied and evaluated by applying them to traction prediction in a sliding elastohydrodynamic point contact. Numerical calculations, using measured film thickness and surface temperature data, were compared with measured tractions under several conditions of normal load and sliding speed. In addition, the theory was used to study the effect on the traction of variations in the lubricant material properties.

scholarly journals Redesigning and Manufacturing of a Land Levelling Shovel by Assembly Structural Stress Analysis

2014 ◽  
Vol 6 ◽  
pp. 235687 ◽  
Author(s):  
Tahir Altinbalik ◽  
Gürkan İrsel
Keyword(s):  
Stress Analysis ◽  
Maximum Stress ◽  
Stress Conditions ◽  
Present Condition ◽  
Structural Stress ◽  
Loading Conditions ◽  
Design Studies ◽  
Connection System ◽  
New Construction ◽  
Bolt Connection

The aim was to redesign and manufacture of a shovel for a pull-type land levelling machine, which, in its present condition, is used to get easily damaged even under low loads. Firstly, the maximum pulling load affecting the levelling shovel was experimentally determined. Then, stable-shovel system with the bolt connection was replaced with a bearing-shaft connection system. In this way, the new shovel has gained a capability of making oscillation motion so that it can operate on sloped grounds. CATIA program was used in the design studies. The shovel system was investigated by assembly structural stress analyses. This new construction enabled the system to operate 3 times more securely at maximum stress conditions without changing the levelling shovel material. Thus, it is managed to prevent any possible damages that might occur due to maximum loading conditions of the system. Besides, displacements that occur on the shovel decreased at the rate of 90%.

CAD/CAE for stress–strain properties of multifilament twisted yarns

2016 ◽  
Vol 87 (6) ◽  
pp. 657-668 ◽  
Author(s):  
Keartisak Sriprateep ◽  
Erik LJ Bohez
Keyword(s):  
Computer Aided Design ◽  
Maximum Stress ◽  
Tensile Behavior ◽  
Assembly Model ◽  
The Finite Element Method ◽  
Stress Strain ◽  
Filament Assembly ◽  
Computer Aided ◽  
Aided Design ◽  
Good Agreement

A method is presented for modeling the tensile behavior of multifilament twisted yarns. A filament assembly model and a computer-aided design/computer-aided engineering (CAD/CAE) approach are proposed for the tensile analysis. The geometry of the twisted yarn and the nonlinear filament properties were considered. The finite element method (FEM) and large deformation effects were applied for computation of the stress–extension curves. Ideal yarn structures of five layers with different twist angles were simulated to predict the tensile behavior of each filament and each layer. The stress acting on the filaments after yarn extension could be directly analyzed by the FEM. The stress distribution in the filaments showed that the highest stress regions were located at the filament in the center of the yarn and decreased slightly to the yarn surface. The stress–extensions of the filaments were converted to yarn tensile behavior that is shown in terms of the maximum and average stress–extension curves. The results of this prediction model were compared with the stress–strain curves of high-tenacity rayon yarn and the energy method. The maximum stress–extension curves showed very good agreement with experimental results and are more accurate than those obtained by previous methods.

A strain-based tensor polynomial failure criterion for anisotropic materials

1988 ◽  
Vol 23 (4) ◽  
pp. 179-186 ◽  
Author(s):  
W Zhang ◽  
K E Evans
Keyword(s):  
Epoxy Resin ◽  
Plane Stress ◽  
Failure Criterion ◽  
Maximum Stress ◽  
Failure Criteria ◽  
Anisotropic Materials ◽  
Maximum Strain ◽  
Stress Space ◽  
Failure Envelope ◽  
Stress Maximum

A strain-based tensor polynomial failure criterion for anisotropic materials is proposed with explicit derivations given in both strain and stress space. The physical distinction between this strain-based criterion and the current stress-based tensorial criterion of Tsai and Wu, is clarified. The viability of the proposed criterion is shown by its application to a graphite—epoxy resin lamina under plane stress. The allowed loadings and failure envelope of this lamina are predicted. Comparison is made with existing failure criteria (both stress-based and strain-based), in particular the maximum stress, maximum strain, and Tsai-Wu criteria.

TEM sample preparation of transparent polycrystalline alumina: Correlation between optical microscopy and TEM images

1992 ◽  
Vol 50 (1) ◽  
pp. 404-405
Author(s):  
K.J. Ostreicher ◽  
C.M. Sung
Keyword(s):  
Sample Preparation ◽  
Optical Microscopy ◽  
Grain Orientation ◽  
Research Effort ◽  
Good Method ◽  
Preparation Process ◽  
Orientation Relationships ◽  
Polycrystalline Alumina ◽  
Pull Out ◽  
Grain Size And Shape

Since the discovery of the Lucalox process, a considerable amount of research effort has been devoted to locating both impurities and additives in transparent polycrystalline alumina (PCA). The control of grain growth and porosity by introducing dopants such as MgO and Y2O3 has been shown to directly affect the strength and transmittance properties of the material. The presence of impurities or dopants in excess of their solubility limits leads to precipitation in the bulk and along grain boundaries. It is essential that TEM sample preparation be controlled so as not to introduce damage or pull-out of sec materials it becomes a good method to obtain information concerning grain size and shape, grain orientation relationships, and porosity. The purpose of this study is to describe such a sample preparation process and demonstrate its usefulness in allowing effective correlation of optical microscopy and TEM results.

Effect of Load Direction on Failure of Out-of-Plane Composite Joints

2015 ◽  
Vol 1095 ◽  
pp. 934-937
Author(s):  
Yu Li Chen ◽  
Kang Kang Wang ◽  
Xiao Xiao Zhang
Keyword(s):  
Failure Criterion ◽  
Maximum Stress ◽  
Tensile Load ◽  
Load Direction ◽  
Stretch Bending ◽  
Fabric Composite ◽  
Bending Load ◽  
Out Of Plane ◽  
Ultimate Failure ◽  
Bending Loads

The mechanical properties of fabric composite π joints under stretch-bending load are studied using the progressive damage method. The failure mode of fillers is evaluated by the modified maximum stress failure criterion due to their structural particularity, while other parts of the joint by the maximum stress failure criterion. Compared with the results of joints under simple tensile load, the numerical simulation result of the joint under stretch-bending loads with varied directions reveals that the flexion can cause significant reduction in the initial and ultimate failure strength although it has little effect on the structure stiffness before initial failure. In addition, the base laminate and the skin are more easily damaged under stretch-bending loads.

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