scholarly journals Strip on elastic foundation described by different models, loaded by evenly distributed load

2021 ◽  
pp. 217
Author(s):  
Vitaly Kozhushko ◽  
Sergei Krasnov
Keyword(s):  
Elastic Foundation ◽  
Bending Moments ◽  
Joint Work ◽  
Soil System ◽  
Method Of Calculation ◽  
Winkler Model ◽  
Distributed Load ◽  
Calculation Results ◽  
Soil Foundation ◽  
Ground Structures

The problem of changing the size of the reactive pressures perceived by a strip at use of various models of the soil foundation and at various indicators of flexibility of the “strip-soil” system is investigated. The aim of the work is to obtain the form of plots of reactive pressures produced by the soil foundation on a strip loaded along its entire length with a uniformly distributed load. In determining the values ​​of reactive pressures and values ​​of bending moments, the data of a previously published work of one of the authors of the article, based on V.N. Zhemochkin method, is used. Analysis of the obtained calculation results showed that the shape of the plot of reactive pressures largely depends on both the index of flexibility of the foundation and the index of flexibility of the “strip-soil” system. The novelty of the research is that the calculation results are obtained using the traditional method of calculation (i.e., without taking into account the joint work of the “strip-soil” system and using 3 models of the soil base: linearly deformable half-plane, linearly deformable layer of finite thicknesses and the Winkler model. The obtained results of calculation will allow to design ground structures on the elastic foundation.

Large Deflection of a Rectangular Plate Resting on a Pasternak-Type Elastic Foundation

1977 ◽  
Vol 44 (3) ◽  
pp. 509-511 ◽  
Author(s):  
P. K. Ghosh
Keyword(s):  
Rectangular Plate ◽  
Elastic Foundation ◽  
Large Deflection ◽  
Lateral Load ◽  
Bending Moments ◽  
Shear Forces ◽  
Simply Supported ◽  
Base Parameters ◽  
Square Plate

The problem of large deflection of a rectangular plate resting on a Pasternak-type foundation and subjected to a uniform lateral load has been investigated by utilizing the linearized equation of plates due to H. M. Berger. The solutions derived and based on the effect of the two base parameters have been carried to practical conclusions by presenting graphs for bending moments and shear forces for a square plate with all edges simply supported.

Effect of Torsion on Collapse Bending Moment for 24-Inch Diameter Schedule 80 Pipes With Wall Thinning

2012 ◽  
Author(s):  
Kunio Hasegawa ◽  
Yinsheng Li ◽  
Bostjan Bezensek ◽  
Phuong Hoang
Keyword(s):  
Power Plants ◽  
Bending Moment ◽  
Combined Loading ◽  
Bending Moments ◽  
Compressive Stresses ◽  
Wall Thinning ◽  
Nominal Thickness ◽  
Calculation Results ◽  
Loading Modes ◽  
Local Wall Thinning

Piping items in power plants may experience combined bending and torsion moments during operation. Currently, there is a lack of guidance in the ASME B&PV Code Section XI for combined loading modes including pressure, torsion and bending. Finite element analyses were conducted for 24-inch diameter Schedule 80 pipes with local wall thinning subjected to tensile and compressive stresses. Plastic collapse bending moments were calculated under constant torsion moments. From the calculation results, it can be seen that collapse bending moment for pipes with local thinning subjected to tensile stress is smaller than that subjected to compressive stress. In addition, equivalent moment is defined as the root the sum of the squares of the torsion and bending moments. It is found that the equivalent moments can be approximated with the pure bending moments, when the wall thinning length is equal or less than 7.73R·t for the wall thinning depth of 75% of the nominal thickness, where R is the mean radius and t is the wall thickness of the pipe.

Analysis by the mixed method of statically indeterminate frames with elements of increased rigidity and numerical verification of the calculation results using the finite element method

2021 ◽  
Vol 14 (2) ◽  
pp. 54-66
Author(s):  
Svetlana Sazonova ◽  
Viktor Asminin ◽  
Alla Zvyaginceva
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Initial Data ◽  
Mixed Method ◽  
Numerical Verification ◽  
Bending Moments ◽  
The Finite Element Method ◽  
Calculation Results ◽  
Internal Forces ◽  
Element Method

The sequence of application of the mixed method for calculating internal forces in statically indeterminate frames with elements of increased rigidity is given. The main system is chosen for the frame with one kinematic and one force unknown. The canonical equations of the mixed method are written, taking into account their meaning. Completed the construction of the final diagram of the bending moments and all the necessary calculations and checks. When calculating integrals, Vereshchagin's rule is applied. The solution of the problem is checked by performing the calculation using the computer program STAB12.EXE; the results of the calculations are numerically verified using the finite element method. An example of the formation of the initial data for the STAB12.EXE program and the subsequent processing of the calculation results, the rules for comparing the numerical results and the results obtained in the calculation of the frame by the mixed method are given.

scholarly journals Optimization of the truss beam. Verification of the calculation results

2018 ◽  
Vol 230 ◽  
pp. 02037 ◽  
Author(s):  
Glib Vatulia ◽  
Sophia Komagorova ◽  
Mykhailo Pavliuchenkov
Keyword(s):  
Theoretical Calculations ◽  
Optimality Criteria ◽  
Constant Load ◽  
Bending Moments ◽  
Convergence Criteria ◽  
Variable Parameters ◽  
Software Complex ◽  
Comparison Of Results ◽  
Calculation Results ◽  
Construction Optimization

The article presents a comparison of results of optimized calculation of a truss beam which was chosen as a combined construction. The results of calculation of a beam are compared using the method based on the properties of spacer systems and the calculation of the construction designed in LIRA software complex. The article is dedicated to verification of adequacy of the results of theoretical calculations of construction optimization. Values of longitudinal forces and bending moments appearing in a truss beam are chosen as convergence criteria. Two variants of construction loading are considered: a truss beam exposed to constant load only and a truss beam exposed to constant and temporary load. In the case under consideration, the minimum value (weight) of construction is an optimality criteria, variable parameters include beam panel length and camber height of a trussing rod. As a result, the construction will be considered optimal, if bearing and maximal (between the pillars) bending moments are equal in it. The result of verification of the obtained data is the value of error.

scholarly journals Determining internal forces in modular building elements under action wind load

2018 ◽  
Vol 196 ◽  
pp. 02010
Author(s):  
Viacheslav Shirokov ◽  
Alexey Soloviev ◽  
Tatiana Gordeeva
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cross Section ◽  
Dynamic Characteristics ◽  
Wind Load ◽  
Wind Loads ◽  
Bending Moments ◽  
The Finite Element Method ◽  
Calculation Results ◽  
Internal Forces

The research paper focuses on internal forces determination in the elements of modular buildings under wind load. It provides a methodology for determining dynamic characteristics of a building and for calculating wind loads. This method is based on the following assumptions: coupling of the modules elements is rigid; coupling of block-modules with foundations is hinged-fixed; connection of blocks to each other is hinged in angular points; the floor disk in its plane is not deformed. On the basis of these assumptions the authors derived approximate and refined equations for determining forces in modules elements under static and pulsation components of wind load. The equation of bending moments determination in the pillar bearing cross-section is obtained by approximation of the graph of moments variation, calculated for the spectrum of the ratio of the pillar stiffness and the floor beam in the range from 1/64 to 64. The paper further introduces the calculation results of forces based on the proposed methodology and on the finite element method. The calculations were done while taking different values of wind load and different number of storeys in a building (from 1 to 4 floors). The obtained results are similar, the error does not exceed 5%.

scholarly journals Geotechnical and ecological foundations of the sustainable life cycle of the long-operated unique underground structures of the water disposal system in difficult ground conditions

2019 ◽  
Vol 265 ◽  
pp. 05002
Author(s):  
Nicolay Perminov
Keyword(s):  
Life Cycle ◽  
Operational Reliability ◽  
Technical Condition ◽  
Simultaneous Increase ◽  
Underground Structures ◽  
Joint Work ◽  
Soil System ◽  
Ground Conditions ◽  
Condition Modeling ◽  
Water Disposal

Intensive development of megacities causes the need for sustainable operation of underground urban infrastructure facilities. In the special protection against man-made impact, long-operated unique underground structures of the water disposal system, which are related to facilities with an increased level of responsibility and danger, are needed. In the report, based on the experience of studying the operation of underground wastewater facilities in conditions of weak soils and intensive external static and dynamic impacts, there are proposed new methods for diagnosing their technical condition, modeling and monitoring of the joint work of the "underground structures aggregate of soil" system are implemented, forecasting and shaping conditions for its sustainable life cycle. Point and linear objects of the water canal of St. Petersburg are developed and implemented at unique (to a depth of 70 m.) geotechnology, providing simultaneous increase of bearing capacity, operational reliability and ecological safety of longoperated underground drainage facilities in difficult ground conditions with increasing man-caused impacts.

Design of Crane Hooks and Other Components of Lifting Gear

1934 ◽  
Vol 128 (1) ◽  
pp. 253-360 ◽  
Author(s):  
H. J. Gough ◽  
H. L. Cox ◽  
D. G. Sopwith
Keyword(s):  
Fatigue Testing ◽  
Ductile Material ◽  
Radius Of Curvature ◽  
Stress System ◽  
Bending Moments ◽  
Approximate Methods ◽  
Method Of Calculation ◽  
Centre Line ◽  
Set Up ◽  
Chain Links

Most lifting gear components consist essentially of curved beams of very ductile material, the radius of curvature often being small in comparison with the dimensions of the beam. In addition, in rings, chain links, etc., the distribution of bending moment is not directly calculable from the values of the applied loads, but is influenced also by the condition that the centre line of the section of the component must remain continuous when under load. The design of lifting gear components requires, therefore, the determination of the bending moments, etc., set up, the calculation of the stresses due to these bending moments, etc., and the consideration of the modification to the stress system consequent upon yielding in parts of the components. The effect of the curvature of the centre line of the component on the distribution of stress is first discussed, the method of calculation for different forms of beam section being indicated, and the best form of section investigated. The effect of yielding is next considered. It is shown that, if any portion of the component yields under load, the removal of the load will leave this portion in a state of stress of opposite sign to that under which it yielded, and it is concluded that calculated stresses even as high as the sum of the yield stresses in tension and compression may be actually set up in the material as ranges of stress without causing continuous plastic deformation. The general method of calculating the bending moments in rings and links, etc., is demonstrated and comparison is made between exact and approximate methods. General formulæ for egg links (including rings and chain links), studded links, and eyebolts are obtained and typical examples, drawn from recent British Standard Specifications, are worked out. The results of tests on components designed according to the general principles of the paper are described and the use of fatigue testing both in determining the true factor of safety and as an experimental check on the calculations is demonstrated.

Dynamic Analysis of an Integrated Train–Bridge–Foundation–Soil System by the Substructure Method

2018 ◽  
Vol 18 (05) ◽  
pp. 1850069 ◽  
Author(s):  
Hong Qiao ◽  
He Xia ◽  
Xianting Du
Keyword(s):  
Dynamic Analysis ◽  
Shear Velocity ◽  
Rigid Body Dynamics ◽  
Dynamic Responses ◽  
Superposition Method ◽  
Foundation Soil ◽  
Soil System ◽  
Substructure Method ◽  
Soil Foundation ◽  
Bridge Foundation

The substructure method is applied to the dynamic analysis of a train–bridge system considering the soil–structure interaction. With this method, the integrated train–bridge–foundation–soil system is divided into the train–bridge subsystem and the soil–foundation subsystem. Further, the train–bridge subsystem is divided into the train and bridge components. The frequency-dependent impedance function of the soil–foundation subsystem is transformed into time domain by rational approximation and simulated by a high-order lumped-parameter model with masses. The equations of motion of the train and bridge components are established by the rigid-body dynamics method and the modal superposition method, respectively. Finally, the dynamic responses of the two subsystems are obtained by iterative procedures, with the influence of the soil shear velocity studied. The case study reveals that it is important to consider the effect of soil–foundation interaction in the dynamic analysis of train–bridge systems, but with the increase of the shear velocity of the soil, such influence becomes weaker.

scholarly journals Numerical analysis of symmetrical and asymmetrical reinforced concrete flat slabs - an integrated slab/ column analysis

2016 ◽  
Vol 9 (3) ◽  
pp. 306-356
Author(s):  
A. Puel ◽  
D. D. Loriggio
Keyword(s):  
Numerical Analysis ◽  
Axial Force ◽  
Three Dimensional ◽  
Bending Moment ◽  
Bending Moments ◽  
Flat Slabs ◽  
Distributed Load ◽  
Significant Difference ◽  
Local Support ◽  
Internal Forces

ABSTRACT This paper studies the modeling of symmetric and asymmetric flat slabs, presenting alternatives to the problem of singularity encountered when the slab is modeled considering columns as local support. A model that includes the integrated slab x column analysis was proposed, distributing the column reactions under the slab. The procedure used transforms the bending moment and column axial force in a distributed load, which will be applied to the slab in the opposite direction of gravitational loads. Thus, the bending moment diagram gets smooth in the punching region with a considerable reduction of values, being very little sensible to the variation of used mesh. About the column, it was not seen any significant difference in the axial force, although the same haven't occurred with the bending moments results. The final part of the work uses geoprocessing programs for a three-dimensional view of bending moments, allowing a new comprehension the behavior of these internal forces in the entire slab.

MODELING AND ANALYSIS OF A PLATE ON ELASTIC FOUNDATION SUBJECTED TO LANDING AIRPLANES' FORCES

2010 ◽  
Vol 10 (01) ◽  
pp. 37-54 ◽  
Author(s):  
T. G. KOSTANTAKOPOULOS ◽  
G. T. MICHALTSOS
Keyword(s):  
Elastic Foundation ◽  
Numerical Study ◽  
Elastic Behavior ◽  
Spring Model ◽  
Modeling And Analysis ◽  
Load Model ◽  
Winkler Model ◽  
Mass Load ◽  
Plate On Elastic Foundation ◽  
Plate Deflection

This paper deals with the problem of the dynamic behavior of a plate on elastic foundation under the action of forces produced by a landing airplane. A partially plastic impact is postulated for the contact between the airplane and the plate. The Winkler model is used to simulate the ground's elastic behavior, by which the foundation reaction is proportional to the plate deflection, along with dampers for energy dissipation. Two models are used for the airplane, i.e. a simplified mass-load model and a mass-dashpot-spring model, and their influences on the dynamic response of the plate are evaluated. Moreover, various parameters concerning the salient features of the airplane and its landing on the plate are studied with conclusions drawn. The efficiency of the methodology proposed herein was demonstrated in the numerical study.

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