Optimum Design of Intermediate Support for Raising Fundamental Frequency of a Beam or Column under Compressive Axial Load

2014 ◽  
Vol 140 (7) ◽  
pp. 04014040
Author(s):  
D. Wang
Keyword(s):  
Fundamental Frequency ◽  
Optimum Design ◽  
Axial Load ◽  
Intermediate Support ◽  
Compressive Axial Load

Photoelastic Analysis on Different Retention Methods of Implant-Supported Prosthesis

2015 ◽  
Vol 41 (3) ◽  
pp. 258-263 ◽  
Author(s):  
Angélica Castro Pimentel ◽  
Marcello Roberto Manzi ◽  
Cristiane Ibanhês Polo ◽  
Claudio Luiz Sendyk ◽  
Maria da Graça Naclério-Homem ◽  
...  
Keyword(s):  
Stress Distribution ◽  
Axial Load ◽  
Testing Machine ◽  
Compressive Load ◽  
Lower Intensity ◽  
Photoelasticity Method ◽  
Universal Testing ◽  
Isochromatic Fringes ◽  
Photoelastic Analysis ◽  
Compressive Axial Load

The aim of this study was to evaluate the stress distribution of different retention systems (screwed, cemented, and mixed) in 5-unit implant-supported fixed partial dentures through the photoelasticity method. Twenty standardized titanium suprastructures were manufactured, of which 5 were screw retained, 5 were cement retained, and 10 were mixed (with an alternating sequence of abutments), each supported by 5 external hexagon (4.0 mm × 11.5 mm) implants. A circular polariscope was used, and an axial compressive load of 100 N was applied on a universal testing machine. The results were photographed and qualitatively analyzed. We observed the formation of isochromatic fringes as a result of the stresses generated around the implant after installation of the different suprastructures and after the application of a compressive axial load of 100 N. We conclude that a lack of passive adaptation was observed in all suprastructures with the formation of low-magnitude stress in some implants. When cemented and mixed suprastructures were subjected to a compressive load, they displayed lower levels of stress distribution and lower intensity fringes compared to the screwed prosthesis.

Analysis of Shear-critical reinforced concrete columns under variable axial load

2022 ◽  
pp. 1-24
Author(s):  
Dimitrios K. Zimos ◽  
Panagiotis E. Mergos ◽  
Vassilis K. Papanikolaou ◽  
Andreas J. Kappos
Keyword(s):  
Reinforced Concrete ◽  
Axial Load ◽  
Shear Failure ◽  
Progressive Collapse ◽  
Full Range ◽  
Element Model ◽  
Independent Verification ◽  
Lateral Response ◽  
Proposed Model ◽  
Compressive Axial Load

Older existing reinforced concrete (R/C) frame structures often contain shear-dominated vertical structural elements, which can experience loss of axial load-bearing capacity after a shear failure, hence initiating progressive collapse. An experimental investigation previously reported by the authors focused on the effect of increasing compressive axial load on the non-linear post-peak lateral response of shear, and flexure-shear, critical R/C columns. These results and findings are used here to verify key assumptions of a finite element model previously proposed by the authors, which is able to capture the full-range response of shear-dominated R/C columns up to the onset of axial failure. Additionally, numerically predicted responses using the proposed model are compared with the experimental ones of the tested column specimens under increasing axial load. Not only global, but also local response quantities are examined, which are difficult to capture in a phenomenological beam-column model. These comparisons also provide an opportunity for an independent verification of the predictive capabilities of the model, because these specimens were not part of the initial database that was used to develop it.

Dynamic and Stability Analysis of the Rotating Nanobeam in a Nonuniform Magnetic Field Considering the Surface Energy

2016 ◽  
Vol 08 (04) ◽  
pp. 1650048 ◽  
Author(s):  
M. Baghani ◽  
M. Mohammadi ◽  
A. Farajpour
Keyword(s):  
Magnetic Field ◽  
Stability Analysis ◽  
Angular Velocity ◽  
Surface Energy ◽  
Axial Load ◽  
Nonuniform Magnetic Field ◽  
Small Scale ◽  
Stability Behavior ◽  
Compressive Axial Load ◽  
The Stability

It is well-known that rotating nanobeams can have different dynamic and stability responses to various types of loadings. In this research, attention is focused on studying the effects of magnetic field, surface energy and compressive axial load on the dynamic and the stability behavior of the nanobeam. For this purpose, it is assumed that the rotating nanobeam is located in the nonuniform magnetic field and subjected to compressive axial load. The nonlocal elasticity theory and the Gurtin–Murdoch model are applied to consider the effects of inter atomic forces and surface energy effect on the vibration behavior of rotating nanobeam. The vibration frequencies and critical buckling loads of the nanobeam are computed by the differential quadrature method (DQM). Then, the numerical results are testified with those results are presented in the published works and a good correlation is obtained. Finally, the effects of angular velocity, magnetic field, boundary conditions, compressive axial load, small scale parameter and surface elastic constants on the dynamic and the stability behavior of the nanobeam are studied. The results show that the magnetic field, surface energy and the angular velocity have important roles in the dynamic and stability analysis of the nanobeams.

Optimal Forms of Shallow Cylindrical Panels With Respect to Vibration and Stability

1986 ◽  
Vol 53 (1) ◽  
pp. 135-140 ◽  
Author(s):  
R. H. Plaut ◽  
L. W. Johnson
Keyword(s):  
Surface Area ◽  
Fundamental Frequency ◽  
Axial Load ◽  
Cylindrical Panel ◽  
Buckling Load ◽  
Material Surface ◽  
Uniform Thickness ◽  
Simply Supported ◽  
Cylindrical Panels

Thin, shallow, elastic, cylindrical panels with rectangular planform are considered. We seek the midsurface form which maximizes the fundamental frequency of vibration, and the form which maximizes the buckling value of a uniform axial load. The material, surface area, and uniform thickness of the panel are specified. The curved edges are simply supported, while the straight edges are either simply supported or clamped. For the clamped case, the optimal panels have zero slope at the edges. In the examples, the maximum fundamental frequency is up to 12 percent higher than that of the corresponding circular cylindrical panel, while the buckling load is increased by as much as 95 percent. Most of the solutions are bimodal, while the rest are either unimodal or trimodal.

Vibration of a Standing Heavy Column With Intermediate Support

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
C. Y. Wang
Keyword(s):  
Fundamental Frequency ◽  
Optimum Location ◽  
Initial Value ◽  
Free Standing ◽  
Intermediate Support ◽  
Exact Relations

The vibration of a free standing column under its own weight is studied. An intermediate support increases the fundamental frequency. The optimum location for the support is determined for clamped-free, pinned-free, and sliding-free columns. The problem is integrated by a simple accurate initial value method. Approximate and exact relations are also found.

scholarly journals Contribution of Transverse Reinforcement Configuration on Concrete Shear Capacity of RC Column

2020 ◽  
Vol 8 (3) ◽  
pp. 127-136
Author(s):  
Taufiq Saidi ◽  
Rudiansyah Putra ◽  
Zahra Amalia ◽  
Munawir Munawir
Keyword(s):  
Axial Load ◽  
Shear Failure ◽  
Shear Capacity ◽  
Transverse Reinforcement ◽  
Shear Load ◽  
Test Results ◽  
Rc Column ◽  
Proper Design ◽  
Compressive Axial Load ◽  
Reinforcement Configuration

Proper design of transverse reinforcement in the RC column is needed to maintain its ability to deform under axial and shear load safely. Even though mandatory building codes for transverse support of the RC column exist, shear failure was still found in the last high earthquake in Pidie, Aceh, in 2016. Therefore, as an attempt to improve RC column strength and elasticity, the effect of transverse reinforcement configuration was evaluated experimentally to a column subjected to an axial and shear load. The experiment was conducted by using four-column specimens with a cross-section 200 x 200 mm. Four types of transverse reinforcement configurations were applied in each column. The test was carried out by loading an axial load always and shear load gradually until its failure. The test results show that the configuration of transverse reinforcement has a significant effect of maintaining column stiffness, which was subjected to compressive axial load and shear load. Furthermore, the arrangement of transverse reinforcement influences the compressive strength significantly and enhance the concrete shear capacity of a column due to its confinement effect.

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