scholarly journals Resistance of models of pyramidal-prismatic piles to static pulling load

2021 ◽  
Vol 134 (1) ◽  
pp. 7-19
Author(s):  
◽  
M.I. Nikitenko ◽  
N.А. Shanshabayev ◽  
◽  
Keyword(s):  
Bearing Capacity ◽  
Cross Section ◽  
Longitudinal Section ◽  
Laboratory Conditions ◽  
Pull Out ◽  
Section Shape ◽  
Section Size ◽  
The Stability

The article presents results of testing models of piles with different longitudinal shapes under the action of a static pulling load, performed in laboratory conditions. The article reveals resistance of the pyramidal-prismatic piles can be either more or less than the resistance of the prismatic and pyramidal piles. It was found that an increase in the length of the pyramidal part of the pile, as well as the size of its cross-section at the top, affect the resistance of the pile to pull-out load. So, the resistance of these piles is 1.28-1.85 times higher than the resistance of a prismatic pile with a section size of 20×20 cm, and 8-36% lower than the resistance of a prismatic pile with a section size of 30×30 cm and a pyramidal pile (with a top section size of 30×30 cm and at the bottom - 20×20 cm). Correlation dependencies are obtained to assess the stability of pyramidal-prismatic piles in relation to the bearing capacity of piles with traditional longitudinal section shape (prismatic and pyramidal piles).

CALCULATION OF EFFORTS RIPS FOUNDATION BOLTS IN THE BCALCULATION OF EFFORTS RIPS FOUNDATION BOLTS IN THE BASES OF CENTRAL AND ECCENTRIC COMPRESSION COLUMNASES OF CENTRAL AND ECCENTRIC COMPRESSION COLUMN

2021 ◽  
Vol 295 (2) ◽  
pp. 32-36
Author(s):  
A.E. Svyatoshenko ◽  
◽  
Keyword(s):  
Cross Section ◽  
Software Package ◽  
Calculation Model ◽  
Neutral Axis ◽  
Continuous Section ◽  
Eccentric Compression ◽  
Engineering Technique ◽  
Section Shape ◽  
Longitudinal Bending ◽  
The Stability

An engineering technique for calculating the tearing forces in the foundation bolts in the bases of centrally compressed columns is proposed. The calculation of the forces is based on the calculation of extra-centrally compressed rods, taking into account: the influence of the cross-section shape; the initial curvature of the neutral axis of the column; random eccentricity; nonlinear steel work. The calculation of the attachment forces (Nult and Mfic) of columns on the foundation edge is based on the method of practical calculations of centrally compressed elements using the stability coefficients at central compression φ (longitudinal bending coefficients), which are calculated depending on the flexibility l. The calculation of the attachment forces for rods with different reduced flexibility was performed by FEM in the FEMAP software package, as well as analytically using fictitious forces in centrally compressed rods. To calculate the tearing forces in the foundation bolts, a calculation model is made taking into account the contact interaction of the base and the reinforced concrete base. Graphs of the effect of the flexibility of the centrally compressed rod on the tearing force in the foundation bolts at the stage of exhaustion of the bearing capacity of the column when calculating its stability as an element of a continuous section under central compression are constructed.

Influence of Gravity and Taper on the Vibration of a Standing Column

2012 ◽  
Vol 4 (04) ◽  
pp. 483-495 ◽  
Author(s):  
C. Y. Wang
Keyword(s):  
Cross Section ◽  
Numerical Stability ◽  
Natural Vibration ◽  
Vibration Frequencies ◽  
Stability Criteria ◽  
Initial Value ◽  
Vertical Column ◽  
Stability Boundaries ◽  
Section Shape ◽  
The Stability

AbstractThe stability and natural vibration of a standing tapered vertical column under its own weight are studied. Exact stability criteria are found for the pointy column and numerical stability boundaries are determined for the blunt tipped column. For vibrations we use an accurate, efficient initial value numerical method for the first three frequencies. Four kinds of columns with linear taper are considered. Both the taper and the cross section shape of the column have large influences on the vibration frequencies. It is found that gravity decreases the frequency while the degree of taper may increase or decrease frequency. Vibrations may occur in two different planes.

Modeling the Phonon Transport in Nanowire with Different Cross-Section

2013 ◽  
Vol 401-403 ◽  
pp. 852-855
Author(s):  
Gao Hui Su ◽  
Zi Chun Yang ◽  
Feng Rui Sun
Keyword(s):  
Thermal Conductivity ◽  
Cross Section ◽  
Diffuse Reflection ◽  
Silicon Nanowire ◽  
Circular Cross Section ◽  
Phonon Transport ◽  
Reflection Mode ◽  
Section Shape ◽  
Section Size ◽  
The Cross

The phonon transport in silicon nanowire was simulated by Monte Carlo Method (MCM). The effect on the phonon transport of the boundary reflection mode, cross-section size and cross-section shape was studied. Analysis shows that diffuse reflection can result in phonon accumulation at the circumferential boundary. As the cross-section size decrease, the nonuniformity of the temperature distribution within the cross-section becomes more severe. When the area of the square cross-section silicon nanowire (SCSN) is equal to that of the circular cross-section silicon nanowire (CCSN), the thermal conductivity of them is more close to each other.

Research of Direct Calculation Method for Design on Cross-Section of Retaining Wall

2013 ◽  
Vol 639-640 ◽  
pp. 714-717
Author(s):  
Wei Huang
Keyword(s):  
Bearing Capacity ◽  
Cross Section ◽  
Calculation Method ◽  
Calculated Result ◽  
Conversion Factor ◽  
Retaining Wall ◽  
Direct Calculation ◽  
Allowable Range ◽  
The Stability ◽  
Base Width

Based on meeting the requirement of ground bearing capacity, the allowable range of anti-overturning safety factor is derived. The relative parameters are expressed with base width and the relation graphs of conversion factor are presented, and then can design the cross-section of retaining wall directly by combining the stability requirement of anti-sliding. The calculated result shows that this method makes the design simple and reliable. It may be a reference for engineers.

Experiments on Wall Panels with One-Sided Board Sheathing for Timber Structures

2017 ◽  
Vol 1144 ◽  
pp. 3-8
Author(s):  
Jiří Celler ◽  
Jakub Dolejs ◽  
Vera Hlavata
Keyword(s):  
Bearing Capacity ◽  
Cross Section ◽  
Timber Structures ◽  
Bearing Material ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Glued Laminated Timber ◽  
Wall Panels ◽  
The Stability ◽  
Shaped Cross Section

Timber elements with an I-shaped cross-section are used as supporting elements in wall, ceiling and roof panels of light timber frames. The reinforcement of the panel (I-stud) is provided by means of glued timber composite I-shaped element consisting of a web made of a wood-based desk embedded into flanges of solid or glued laminated timber. The stability of the wall panels is usually ensured by sided board sheathing, which prevents buckling of studs in the plane of the wall or their twist. Walls with one-side board sheathing are used for some types of modern timber structures and their load bearing capacity is determined for situation when one-side sheathing burns down during fire or sheathing is not made of a load-bearing material.

scholarly journals Influence of Cross-Sectional Shape on the Mechanical Properties of Concrete Canvas and CFRP-Reinforced Columns

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Jiangang Niu ◽  
Wenming Xu ◽  
Jingjun Li ◽  
Jian Liang
Keyword(s):  
Bearing Capacity ◽  
Axial Compression ◽  
Cross Section ◽  
Load Capacity ◽  
Fiber Reinforced Polymer ◽  
Strengthening Effect ◽  
Fiber Reinforced ◽  
Elliptical Cross ◽  
Reinforced Polymer ◽  
Section Shape

Fiber-reinforced polymer (FRP) wrapping has become an attractive strengthening technique for concrete columns. However, the ingress of corrosion into the concrete through the gap of CFRP fiber greatly reduces the durability of concrete and the bearing capacity of specimens. Concrete canvas, a kind of corrosion-resistant and refractory material, is a promising method to enhance durability and carrying capacity. In this study, the concrete canvas (CC) and carbon fiber-reinforced polymer (CFRP) were used to jointly reinforce columns with square cross section, octagonal cross section, circular cross section, and elliptical cross section. The influence of section shape on the strengthening effect of the axial compression column was investigated by the axial compression test. The results showed that the section shape had a significant influence on the reinforcement effect of the axial compression column. The carrying load capacity and ductility coefficient of different columns follow this order: square column < oval-shaped columns < octagonal columns < circle columns. The increased amplitude of bearing capacity for the different columns with the increase of CC layers follows this order: square columns < oval-shaped columns < circle column < octagonal columns. Compared with the unconstraint columns, the bearing capacity of adopting two-layer CC columns increased by 129%, 155%, 150%, and 139% for the square, octagonal, circular, and elliptical columns, respectively. The octagonal column has the largest increase range. Compared with the unconstraint columns, the bearing capacity of adopting two-layer CC columns increased by 348%, 318%, 310%, and 296% for the square, octagonal, elliptical, and circular columns, respectively. The square column has the largest increase range. The stress concentration phenomenon of all section shapes was weakened after the CC was used. The application of the CC on CFRP-reinforced columns improves column ductility significantly, with some degree of increase in bearing capacity.

Analysis on Parameters of Wood-Frame Model under Impact Loading

2013 ◽  
Vol 438-439 ◽  
pp. 779-783
Author(s):  
Cui Ling Li ◽  
Shu Ying Qu ◽  
Ruo Yang Wu ◽  
Fan Bo Meng
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Bearing Capacity ◽  
Cross Section ◽  
Impact Loading ◽  
Lateral Stiffness ◽  
Element Analysis ◽  
Section Shape ◽  
Wood Frame ◽  
The Impact

Deflection and stress of different cross section forms and its value are compared by finite element analysis of timberwork design model under the impact loading. The result indicates that decreasing the size of cross section or changing the section shape can effectively avoid the model too heavy and conservative design. In the case of horizontal loads applied on first floor, strengthening the column of first floor obviously reduces the deflection of model and improves the lateral stiffness. Keeping the column size of the first floor and choosing I-section significantly reduce the overall weight on condition of meeting the bearing capacity and stability, it also make the material higher utilization.

scholarly journals The strength of compressed structures with CFRP materials reinforcement when exceeding the cross-section size

2018 ◽  
Vol 33 ◽  
pp. 02060 ◽  
Author(s):  
Petr Polskoy ◽  
Dmitry Mailyan ◽  
Sergey Georgiev ◽  
Viktor Muradyan
Keyword(s):  
Bearing Capacity ◽  
Cross Section ◽  
High Strength ◽  
Material Consumption ◽  
High Rise ◽  
Labour Costs ◽  
Section Size ◽  
Strength And Deformation ◽  
The Cross ◽  
Composite Reinforcement

The increase of high-rise construction volume or «High-Rise Construction» requires the use of high-strength concrete and that leads to the reduction in section size of structures and to the decrease in material consumption. First of all, it refers to the compressed elements for which, when the transverse dimensions are reduced, their flexibility and deformation increase but the load bearing capacity decreases. Growth in construction also leads to the increase of repair and restoration works or to the strengthening of structures. The most effective method of their strengthening in buildings of «High-Rise Construction» is the use of composite materials which reduces the weight of reinforcement elements and labour costs on execution of works. In this article the results of experimental research on strength and deformation of short compressed reinforced concrete structures, reinforced with external carbon fiber reinforcement, are presented. Their flexibility is λh=10, and the cross-section dimensions ratio b/h is 2, that is 1,5 times more, than recommended by standards in Russia. The following research was being done for three kinds of strained and deformed conditions with different variants of composite reinforcement. The results of the experiment proved the real efficiency of composite reinforcement of the compressed elements with sides ratio equal to 2, increasing the bearing capacity of pillars till 1,5 times. These results can be used for designing the buildings of different number of storeys.

Fractionation of polymethylene chains: An electron crystallographic investigation

1986 ◽  
Vol 44 ◽  
pp. 794-795
Author(s):  
Douglas L. Dorset
Keyword(s):  
Cross Section ◽  
Binary Systems ◽  
Linear Chain ◽  
Pure Component ◽  
Organic Substrates ◽  
Crystallographic Investigation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molecular Sizes ◽  
The Stability

A variety of linear chain materials exist as polydisperse systems which are difficultly purified. The stability of continuous binary solid solutions assume that the Gibbs free energy of the solution is lower than that of either crystal component, a condition which includes such factors as relative molecular sizes and shapes and perhaps the symmetry of the pure component crystal structures.Although extensive studies of n-alkane miscibility have been carried out via powder X-ray diffraction of bulk samples we have begun to examine binary systems as single crystals, taking advantage of the well-known enhanced scattering cross section of matter for electrons and also the favorable projection of a paraffin crystal structure posited by epitaxial crystallization of such samples on organic substrates such as benzoic acid.

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