Influence of modification of boundary conditions on load carrying capacity in thin-walled columns in the second order approximation

1993 ◽  
Vol 30 (19) ◽  
pp. 2597-2609 ◽  
Author(s):  
Kolakowski Zbigniew
Keyword(s):  
Boundary Conditions ◽  
Carrying Capacity ◽  
Order Approximation ◽  
Second Order ◽  
Load Carrying Capacity ◽  
Second Order Approximation ◽  
Load Carrying ◽  
Thin Walled

scholarly journals Eigenproblem Versus the Load-Carrying Capacity of Hybrid Thin-Walled Columns with Open Cross-Sections in the Elastic Range

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3468
Author(s):  
Zbigniew Kolakowski ◽  
Andrzej Teter
Keyword(s):  
Cross Sections ◽  
Carrying Capacity ◽  
Ultimate Load ◽  
Equilibrium Path ◽  
Load Carrying Capacity ◽  
Nonlinear Buckling ◽  
Elastic Range ◽  
Load Carrying ◽  
Thin Walled ◽  
Ultimate Load Carrying Capacity

The phenomena that occur during compression of hybrid thin-walled columns with open cross-sections in the elastic range are discussed. Nonlinear buckling problems were solved within Koiter’s approximation theory. A multimodal approach was assumed to investigate an effect of symmetrical and anti-symmetrical buckling modes on the ultimate load-carrying capacity. Detailed simulations were carried out for freely supported columns with a C-section and a top-hat type section of medium lengths. The columns under analysis were made of two layers of isotropic materials characterized by various mechanical properties. The results attained were verified with the finite element method (FEM). The boundary conditions applied in the FEM allowed us to confirm the eigensolutions obtained within Koiter’s theory with very high accuracy. Nonlinear solutions comply within these two approaches for low and medium overloads. To trace the correctness of the solutions, the Riks algorithm, which allows for investigating unsteady paths, was used in the FEM. The results for the ultimate load-carrying capacity obtained within the FEM are higher than those attained with Koiter’s approximation method, but the leap takes place on the identical equilibrium path as the one determined from Koiter’s theory.

Geometric Imperfection Sensitivity and Effect of Constraint Conditions of H-Section Columns under Compression

2010 ◽  
Vol 102-104 ◽  
pp. 140-144
Author(s):  
Yi Ping Wang ◽  
Yong Zang ◽  
Di Ping Wu
Keyword(s):  
Carrying Capacity ◽  
Steel Structures ◽  
Load Carrying Capacity ◽  
Imperfection Sensitivity ◽  
Geometric Imperfection ◽  
Manufacture Process ◽  
Buckling Behavior ◽  
Load Carrying ◽  
Thin Walled ◽  
Tolerance Control

The buckling behavior of thin-walled steel structures under load is still imperfectly understood, in spite of much research over the past 50 years. In this paper, the buckling behaviors of H-section columns under compression have been simulated with ANSYS. In the analysis, contact pairs between column ends and end blocks have been introduced into the model, and the load carrying capacity of the columns with four kinds of end constraint conditions and various typical initial geometric imperfections has been calculated and discussed. The results indicate that the load carrying capacity is most sensitive to the flexural imperfection, and the constraint condition cannot change the imperfection sensitivity of a column under compression, but improving restrain condition can heighten the load carrying capacity. They are helpful to the use and the tolerance control in the manufacture process of thin-walled H-section steel structures.

Analysis of Load-Carrying Capacity of Thin-Walled Closed Beams with Different Slenderness

2014 ◽  
Vol 969 ◽  
pp. 39-44
Author(s):  
Jan Valeš
Keyword(s):  
Cross Section ◽  
Carrying Capacity ◽  
Random Fields ◽  
Capacity Analysis ◽  
Geometrically Nonlinear ◽  
Load Carrying Capacity ◽  
Design Load ◽  
Steel Members ◽  
Load Carrying ◽  
Thin Walled

The presented paper deals with the load-carrying capacity analysis of compress steel members having the square closed (box) cross-section with non-dimensional slenderness 0.6, 0.8, 1.0 a 1.2. The axis of these beams is randomly three-dimensionally curved. Initial curvatures are modelled by random fields applying the LHS method. Load-carrying capacities are then calculated by the geometrically nonlinear solution using the ANSYS program. The results are presented both in form of histograms and of the table. The analysis of load-carrying capacity of beams with individual nonlinear slenderness is carried out, and the values are compared with the values of design load-carrying capacity according to the standard.

scholarly journals Non-Newtonian Effects of Second-Order Fluids on the Hydrodynamic Lubrication of Inclined Slider Bearings

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Siddangouda Apparao ◽  
Trimbak Vaijanath Biradar ◽  
Neminath Bhujappa Naduvinamani
Keyword(s):  
Frictional Force ◽  
Carrying Capacity ◽  
Second Order ◽  
Load Carrying Capacity ◽  
Film Pressure ◽  
Pressure Load ◽  
Slider Bearings ◽  
Highly Nonlinear ◽  
Load Carrying ◽  
Second Order Fluids

Theoretical study of non-Newtonian effects of second-order fluids on the performance characteristics of inclined slider bearings is presented. An approximate method is used for the solution of the highly nonlinear momentum equations for the second-order fluids. The closed form expressions for the fluid film pressure, load carrying capacity, frictional force, coefficient of friction, and centre of pressure are obtained. The non-Newtonian second order fluid model increases the film pressure, load carrying capacity, and frictional force whereas the center of pressure slightly shifts towards exit region. Further, the frictional coefficient decreases with an increase in the bearing velocity as expected for an ideal fluid.

Overall Characteristics of Bearings Lubricated With Ferrofluids

1983 ◽  
Vol 105 (3) ◽  
pp. 466-475 ◽  
Author(s):  
N. Tipei
Keyword(s):  
Boundary Conditions ◽  
Carrying Capacity ◽  
Magnetic Particle ◽  
Journal Bearings ◽  
Load Carrying Capacity ◽  
Pressure Center ◽  
Friction Forces ◽  
Flow Rates ◽  
Load Carrying ◽  
Side Flow

Using the results shown in some previous papers, the overall characteristics of bearings lubricated with ferrofluids are calculated. First, the load carrying capacity of infinitely long sliding and journal bearings is considered. The pressure center and the attitude angle are also determined. Then, similar characteristics of finite bearings are obtained. In both cases, the new boundary conditions and the actual film extent under magnetic stresses are taken into account. It is shown that friction forces are mainly affected by the change in viscosity due to magnetic particle suspensions, while magnetic stresses modify friction only under special conditions which usually are not met in lubrication. In addition, the flow rates and the side flow coefficients are calculated. It is shown that the lubricant leakage can be reduced and even avoided when proper measures are taken. For short bearings, diagrams are given for the film extent, the film boundaries, the load carrying capacity, and the attitude of the journal center.

scholarly journals Stability and Load-Carrying Capacity of Thin-Walled FRP Composite Z-Profiles under Eccentric Compression

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2956
Author(s):  
Hubert Debski ◽  
Sylwester Samborski ◽  
Patryk Rozylo ◽  
Pawel Wysmulski
Keyword(s):  
Composite Material ◽  
Carrying Capacity ◽  
Progressive Failure ◽  
Compressive Load ◽  
Experimental Tests ◽  
Numerical Results ◽  
Load Carrying Capacity ◽  
Plastic Composite ◽  
Load Carrying ◽  
Thin Walled

This study investigates the effect of eccentric compressive load on the stability, critical states and load-carrying capacity of thin-walled composite Z-profiles. Short thin-walled columns made of carbon fiber-reinforced plastic composite material fabricated by the autoclave technique are examined. In experimental tests, the thin-walled structures were compressed until a loss of their load-carrying capacity was obtained. The test parameters were measured to describe the structure’s behavior, including the phenomenon of composite material failure. The post-critical load-displacement equilibrium paths and the acoustic emission signal enabling analysis of the composite material condition during the loading process were measured. The scope of the study also included performing numerical simulations by finite element method to solve the problem of non-linear stability and to describe the phenomenon of composite material damage based on the progressive failure model. The obtained numerical results showed a good agreement with the experimental characteristics of real structures. The numerical results are compared with the experimental findings to validate the developed numerical model.

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