Deflection Criteria for Masonry Beams

2007 ◽  
Vol 4 (1) ◽  
pp. 100442
Author(s):  
RM Bennett ◽  
WM McGinley ◽  
J Bryja ◽  
SW Dean
Keyword(s):  
Deflection Criteria

Water Based Colloidal Processing of Ceramic Laminates

2007 ◽  
Vol 333 ◽  
pp. 39-48 ◽  
Author(s):  
Antonio Javier Sanchez-Herencia
Keyword(s):  
Processing Parameters ◽  
Colloidal Processing ◽  
Water Separation ◽  
Green Strength ◽  
Water Based ◽  
The Stability ◽  
Deflection Criteria ◽  
Joining Strength ◽  
Processing Techniques ◽  
Laminated Structures

Multilayered materials and coating are complex structures proposed among others to face the structural requirements of ceramics. The development of reinforcement mechanism by laminated structures can be due to deflection criteria or to the presence of residual stresses and requires of tailored laminates. These designs are characterized by the phases, thickness and distribution of the layers as well as the joining strength between them. In this sense water based colloidal processing techniques are used to fabricate layered structures by consolidating the layers from fluid dispersions of the powders in water. In these processing methods the phases presented in the final laminate are mainly given by the composition of the starting slurries while the changes in thickness and sharpness of the layers are controlled by acting on the processing parameters. The achievement of stable slurries is a shared step for all the colloidal processing techniques. In the water based slurries the stability will be dominated by the polar media, the surface behavior of the particles and the presence of dispersant additives to increase the repulsion between particles. The stable slurry ensures an effective milling and dispersion of the phases as well as high solid loadings, if required. Further processes associated to shaping and consolidation of the layers requires the incorporation of additives and-or water removal. The shaping methods based on aqueous slurries can be classified taking into account the process of solid-water separation. For each of those shaping methods, the nature and amount of the additives is different in order to get the optimum rheological behavior and green strength after drying. Depending on the thickness of layers and coatings as well as the shape and dimensions of the samples, the shaping method can be selected alone and combined with others.

Deflection Criteria for Masonry Beams

Masonry ◽  
2009 ◽  
pp. 39-39-10
Author(s):  
Richard M. Bennett ◽  
William M. McGinley ◽  
Jim Bryja
Keyword(s):  
Deflection Criteria

Determination of Support Minimum Rigid Stiffness for Piping Analysis

2015 ◽  
Author(s):  
Jennifer Huang ◽  
Timothy M. Adams
Keyword(s):  
Lower Bound ◽  
Seismic Response ◽  
Natural Frequency ◽  
Iterative Process ◽  
Piping System ◽  
Alternative Approach ◽  
Formal Procedure ◽  
Deflection Criteria ◽  
Spring Constants

Pipe supports are represented as spring constants in piping analysis, and therefore a formal procedure is required to determine the spring constant values. Two current approaches are to enforce deflection criteria to ensure support rigidity or calculate the support stiffness values directly. However, the former approach results in overly conservative support designs and the latter approach becomes an iterative process of designing the supports and observing the response of the piping system. To avoid the issues presented by these methods, an alternative approach is presented which involves increasing values of support stiffness until change in natural frequency of the system diminishes. This method can help establish a lower bound (minimum rigid) stiffness above which there will be no significant change in the seismic response of the piping system. Using this approach only requires the support designs to have stiffness values at or above the minimum value without being concerned with detailed stiffness calculations or using deflection limits. This paper presents the methods and results of an expansive study to establish minimum rigid stiffness values for piping analysis.

scholarly journals Assessment of a smart concept for d15 shear piezoceramic direct torsion actuation

2011 ◽  
pp. 103-124
Author(s):  
Ayech Benjeddou
Keyword(s):  
Shear Modulus ◽  
Modal Analysis ◽  
Parametric Analysis ◽  
Open Circuit ◽  
Bonding Parameters ◽  
The Core ◽  
Performance Reduction ◽  
And Performance ◽  
Deflection Criteria ◽  
The Cost

An experimentally proved smart concept for piezoceramic direct torsion actuation is here numerically assessed with regards to the bonding and segmentation influence on its behavior and performance. The TRESCA and deflection criteria analysis indicates that the actuator sandwiching with composites contributes to its integrity enhancement, but in the cost of its performance reduction. It is also found that modeling the core inter-rows and composites inter-layers bonding is more influential than that of the core rows segmentation. The conducted open-circuit modal analysis confirms that the inter-rows adhesive softens the actuator, while the inter-layers one stiffens it. Besides, the conducted adhesive parametric analysis indicates that, as expected, the most influential bonding parameters are its thickness and shear modulus.

Crack Deflection at an Interface Between Two Orthotopic Media

1992 ◽  
Vol 59 (2S) ◽  
pp. S79-S87 ◽  
Author(s):  
V. Gupta ◽  
A. S. Argon ◽  
Z. Suo
Keyword(s):  
Material Constant ◽  
Crack Deflection ◽  
Material Parameters ◽  
Fiber Coating ◽  
Composite Systems ◽  
Interfacial Fracture Mechanics ◽  
Orthotropic Media ◽  
Stress And Deformation ◽  
Deflection Criteria ◽  
Brittle Composites

To achieve toughness in many brittle composites, crack deflection at interfaces is essential. For this, it is necessary to establish crack deflection criteria by employing the principles of interfacial fracture mechanics applicable to anisotropic pair of materials. Such an analysis, with two aligned orthotropic media, is considered here. The stress and deformation fields derived for such cases are shown to depend on material parameters λ and p for the two media and on the two so-called Dundur constants α and β. For β = 0, the dependence on λ and λ2 collapses to Λ = (λ1,/λ2)1/4. The delamination criterion is insensitive to λ, p, Λ, and β over practical ranges of these material parameters. Thus, generalized delamination charts become possible as a function of the bi-material constant a alone, which characterizes the elastic dissimilarity between the two media. Using these charts, it is possible to determine the desired level of the interface strength required in composite manufacturing in order to enhance the overall toughness of a composite. Furthermore, such charts can be used for the interfaces between fiber/coating, fiber /matrix, or matrix/coating, depending on which interface is of critical interest for the crack deflection. It is shown how these charts can be used to identify composite systems where it is possible to maximize both the transverse strength and the longitudinal toughness.

Deflection Criteria for Sign Support Structures

1986 ◽  
Vol 112 (10) ◽  
pp. 2332-2341 ◽  
Author(s):  
Mohammad R. Ehsani ◽  
Reidar Bjorhovde
Keyword(s):  
Support Structures ◽  
Sign Support Structures ◽  
Deflection Criteria
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