Micro-Modeling Options for Masonry

2016 ◽  
pp. 28-60 ◽  
Author(s):  
Vasilis Sarhosis
Keyword(s):  
Numerical Methods ◽  
Bond Strength ◽  
Mechanical Behavior ◽  
Data Availability ◽  
Masonry Structures ◽  
Initial State ◽  
Computational Approaches ◽  
Methods Of Analysis ◽  
Full Knowledge ◽  
Micro Modeling

In this chapter, a review of the available methods and their challenges to simulate the mechanical behavior of masonry structures are presented. Different micro-modeling computational options are considered and compared with regard to their ability to define the initial state of the structure, realism in simulation, computer efficiency and data availability for their application to model low bond strength masonry structures. It is highlighted that different computational approaches should lead to different results and these will depend on the adequacy of the approach used and the information available. From the results analysis it is also highlighted that a realistic analysis and assessment of existing masonry structures using numerical methods of analysis is not a straight forward task even under full knowledge of current conditions and materials.

Experimental Study of Adhesion between FRCM and Masonry Support

2014 ◽  
Vol 624 ◽  
pp. 189-196 ◽  
Author(s):  
Valeria Corinaldesi ◽  
Jacopo Donnini ◽  
Giorgia Mazzoni
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Bond Strength ◽  
Cement Matrix ◽  
Masonry Structures ◽  
Matrix Interface ◽  
Mechanical Interaction ◽  
Inorganic Particles ◽  
Ceramic Support

The use of composites with cement matrix seems to acquire an increasing interest in applications to masonry structures, due to their low impact, and a deeper understanding of the mechanical interaction between support and reinforcement is certainly necessary. The effectiveness of these interventions strongly depends on the bond between strengthening material and masonry, on the fibers/matrix interface, as well as on the mechanical properties of the masonry substrate [1]. In this work the attention was focused on the possible improvement of the bond between FRCM and masonry by means of an inorganic primer, which can be spread on the ceramic support before the application of FRCM reinforcement. Two different kinds of brick were tested, in order to simulate more or less porous masonry supports. Results obtained showed that, independently on the kind of brick used (more or less porous) the presence of an inorganic primer always improves bond between masonry support and the cementitiuos matrix of FRCM. In fact, the cementitous matrix of FRCM has been studied and optimized in order to guarantee the best fibers/matrix interface, while it is not necessarily the best option for improving the adhesion with the masonry support. In particular, very effective seems to be the use of very fine inorganic particles (at nanometric scale), which proved to be able to assure the best results in terms of bond strength. Also the fresh consistence of the primer seemed to influence the final result.

scholarly journals All-Sky Radiance Assimilation of ATMS in HWRF: A Demonstration Study

2018 ◽  
Vol 147 (1) ◽  
pp. 85-106 ◽  
Author(s):  
Ting-Chi Wu ◽  
Milija Zupanski ◽  
Lewis D. Grasso ◽  
Christian D. Kummerow ◽  
Sid-Ahmed Boukabara
Keyword(s):  
Single Case ◽  
Control Variable ◽  
Data Availability ◽  
Advanced Technology ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
State Variables ◽  
Initial State ◽  
Clear Sky ◽  
Analysis System

Abstract Satellite all-sky radiances from the Advanced Technology Microwave Sounder (ATMS) are assimilated into the Hurricane Weather Research and Forecasting (HWRF) Model using the hybrid Gridpoint Statistical Interpolation analysis system (GSI). To extend the all-sky capability recently developed for global applications to HWRF, some modifications in HWRF and GSI are facilitated. In particular, total condensate is added as a control variable, and six distinct hydrometeor habits are added as state variables in hybrid GSI within HWRF. That is, clear-sky together with cloudy and precipitation-affected satellite pixels are assimilated using the Community Radiative Transfer Model (CRTM) as a forward operator that includes hydrometeor information and Jacobians with respect to hydrometeor variables. A single case study with the 2014 Atlantic storm Hurricane Cristobal is used to demonstrate the methodology of extending the global all-sky capability to HWRF due to ATMS data availability. Two data assimilation experiments are carried out. One experiment uses the operational configuration and assimilates ATMS radiances under the clear-sky condition, and the other experiment uses the modified HWRF system and assimilates ATMS radiances under the all-sky condition with the inclusion of total condensate update and cycling. Observed and synthetic Geostationary Operational Environmental Satellite (GOES)-13 data along with Global Precipitation Measurement Mission (GPM) Microwave Imager (GMI) data from the two experiments are used to show that the experiment with all-sky ATMS radiances assimilation has cloud signatures that are supported by observations. In contrast, there is lack of clouds in the initial state that led to a noticeable lag of cloud development in the experiment that assimilates clear-sky radiances.

The Mechanical Behavior of Water Vapor-Treated HA Coating Produced by Plasma Spraying Technique

2005 ◽  
Vol 288-289 ◽  
pp. 355-358
Author(s):  
Y. Cao ◽  
Bo Zhang ◽  
Li Ping Wang ◽  
Qiang Lin ◽  
Xu Dong Li ◽  
...  
Keyword(s):  
Water Vapor ◽  
Bond Strength ◽  
Mechanical Behavior ◽  
Metal Substrate ◽  
Ha Coating ◽  
Plasma Sprayed ◽  
Push Out ◽  
Vapor Treatment

Plasma-sprayed hydroxyapatite coating on metal substrate was prepared. Two kind of post-treatment methods were been applied to the coating, treatment in air at 650°C for 30 min and treatment in water vapor at 125°C with a pressure of 0.15MPa for 6 hours. XRD showed that the HA nanocrystals increased after water vapor treatment. The interfacial tensile bond strength between HA and substrate was 45.0±1.82MPa, 39.1±1.27MPa and 30.3±1.61MPa for as-received coatings, water vapor treated coatings and heated in air coatings, respectively. 3 months after implantation in dogs limbs, the push-out strength between implants and bone was 11.27±2.71MPa, 11.63±3.11MPa, 23.92± 2.01MPa and 18.8± 1.82MPa for pure Ti implants, as-received coating implants, water vapor treated implants and heated in air implants, respectively. The results showed that the post-water vapor treated HA coating have better mechanical behavior in vitro and in vivo

Numerical methods for the dynamic analysis of masonry structures

2006 ◽  
Vol 22 (1) ◽  
pp. 107-130 ◽  
Author(s):  
Silvia Degl'Innocenti ◽  
Cristina Padovani ◽  
Giuseppe Pasquinelli
Keyword(s):  
Numerical Methods ◽  
Dynamic Analysis ◽  
Masonry Structures

Investigation of API 8 Round Casing Connection Performance—Part I: Introduction and Method of Analysis

1984 ◽  
Vol 106 (1) ◽  
pp. 130-136 ◽  
Author(s):  
W. T. Asbill ◽  
P. D. Pattillo ◽  
W. M. Rogers
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Internal Pressure ◽  
Mechanical Behavior ◽  
Experimental Analysis ◽  
Strain Gages ◽  
The Finite Element Method ◽  
Strength Of Materials ◽  
Methods Of Analysis ◽  
Element Method

The purpose of this investigation was to gain a better understanding into the mechanical behavior of the API 8 Round casing connection, when subjected to service loads of assembly interference, tension and internal pressure. The connection must provide both structural and sealing functions and these functions were evaluated by several methods. Part I discusses the methods of analysis, which include hand calculations using strength of materials, finite element method via unthreaded and threaded models, and experimental analysis using strain gages. Comparisons of all three methods are made for stresses and show that the finite element method accurately models connection behavior.

Plasticity in the Thickness Direction of Paperboard Under Combined Shear and Normal Loading

2001 ◽  
Vol 123 (2) ◽  
pp. 184-190 ◽  
Author(s):  
N. Stenberg ◽  
C. Fellers ◽  
S. O¨stlund
Keyword(s):  
Mechanical Behavior ◽  
Test Piece ◽  
Yield Function ◽  
Shear Loading ◽  
Plastic Behavior ◽  
Thickness Direction ◽  
Initial State ◽  
Normal Loading ◽  
Elastic Plastic ◽  
Out Of Plane

Creasing and offset printing are both examples of paperboard converting operations where the stress state is multiaxial, and where elastic-plastic deformation occurs in the thickness direction. Optimization of paperboard for such operations requires both advanced modeling and a better understanding of the mechanical behavior of the material. Today, our understanding and modeling of the out-of-plane properties are not as well established as our knowledge of the in-plane behavior. In order to bridge this gap, a modification of the Arcan device, which is well known in other fields, was developed for the experimental characterization of the out-of-plane mechanical behavior of paperboard. A fixture attached to the Arcan device was used to control the deformation in the test piece during loading. The test piece was glued to the device with a high viscosity adhesive and left stress-free during curing to achieve an initial state free of stresses. The apparatus proved to work well and to produce reliable results. Measurements of the mechanical behavior in combined normal and shear loading generated data points for the determination of the yield surface in the stress space. The elastic-plastic behavior in the thickness direction of paperboard was modeled assuming small-strain orthotropic linear elasticity and a quadratic yield function. Simulations using this yield function and an associative flow law showed good agreement with the test results.

scholarly journals The Mechanical Behavior of Grouted Sleeve Splice Connections with and without Mechanical Interlocking Ring Under Axial Tensile Load

2019 ◽  
Vol 9 (2) ◽  
pp. 467-476
Author(s):  
Abdallh M. Soliman ◽  
◽  
Hatem H. Ibrahim ◽  
Hossam A. Hodhod ◽  
◽  
...  
Keyword(s):  
Bond Strength ◽  
Mechanical Behavior ◽  
Research Work ◽  
Tensile Load ◽  
Confining Pressure ◽  
Basic Material ◽  
Bond Behavior ◽  
Axial Tensile ◽  
Steel Sleeve ◽  
Sleeve Wall

This research work thus presents rational procedure to design a grouted sleeve splice connection using a basic material such as standard pipes with little workmanship this provides the design with a good advantage in comparison to just using selection tables for costly proprietary similar connection. The mechanical behavior of such splices is a function of two important mechanisms: the bar-to-grout bond behavior and the sleeve-to-grout bond behavior. To accomplish the goal of this examination work, three arrangements with an all-out number of 66 grouted splice sleeve specimens were fabricated and tested under incremental axial tensile load. The specimens were preliminary designed according to the equations available in the literature to determine the initial sleeve dimensions. Different parameters have been examined, namely: grout compressive strength, bar embedded length, bar diameter, sleeve inner diameter, sleeve wall thickness and sleeve configuration. The examined parameters provide to have a significant impact on the mechanical behavior of the grouted splices. Considering the results, it was clear that steel bars with 18 mm, 25 mm and 32 mm diameter and 044 Mpa yield stress can be adequately spliced and the tensile strength can be reached. The steel sleeve to the grouted splice sleeve connectors significantly improve the bar-to-grout bond strength through the confinement action added by the sleeve wall. Also welding interlocking steel rings can prevent the grout-to-sleeve bond Failure. Feasibility study for tested grouted sleeves reporting their adequacy in accordance with the code provisions of ACI 318-14[1] and ECP 203-2018[5] is presented. Moreover, design equations capturing the parameters affecting the bond strength, the confining pressure, and the required embedment length are derived.

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