scholarly journals Laboratory Study on the Stability of Large-Size Graded Crushed Stone under Cyclic Rotating Axial Compression

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1584
Author(s):  
Bo Tan ◽  
Tao Yang ◽  
Heying Qin ◽  
Qi Liu
Keyword(s):  
Axial Compression ◽  
Failure Load ◽  
Elastic Stability ◽  
Crushed Stone ◽  
Critical Stability ◽  
Stability Performance ◽  
Large Size ◽  
Shakedown Theory ◽  
Cumulative Strain ◽  
The Stability

In this paper, the stability of large-size graded crushed stone used for road base or cushioning under repeated load is investigated. Using an in-house developed device, large-size crushed stone mix was compacted and molded by the vibration and rotary compaction method. Cyclic rotating axial compression was applied, and the shakedown theory was used to study the cumulative deformation of the large-size crushed stone specimens. The effects of gradation parameters on the cumulative strain and stability behavior were analyzed, and the critical stability and failure loads were determined according to the shakedown theory. The test results indicate that there are three obvious instability behavior stages of large-size graded crushed stone under cyclic rotating axial compression: elastic stability, plastic creep, and incremental plastic failure. Large-size graded crushed stone has a higher critical stability load stiffness than conventional-size graded crushed stone. The critical shakedown load of the specimen is mainly affected by the skeleton structure performance, and the critical failure load by the properties of the crushed stone material. Increasing the content and compactness of large-size crushed stone in the specimen can improve the stiffness and stability performance, and to achieve improvements, the content of large-size crushed stone should be controlled between 22% and 26%. The critical shakedown load increases with the increase in the California bearing ratio (CBR) value, while, on the other hand, the CBR value has little relationship with the critical failure load.

Study on Stability Round Stronger Axis of the Column with Composite Section of Double Limbs under Axial Compression

2010 ◽  
Vol 163-167 ◽  
pp. 633-640
Author(s):  
Deng Feng Wang ◽  
Yuan Qing Wang ◽  
Yong Jiu Shi ◽  
Bin Fang
Keyword(s):  
Axial Compression ◽  
Electrostatic Precipitator ◽  
Nonlinear Finite Element ◽  
Thickness Ratio ◽  
Nonlinear Finite Element Method ◽  
Stability Performance ◽  
Composite Section ◽  
Geometrical Imperfections ◽  
The Stability ◽  
Flexural Torsional Buckling

The section of the column under axial compression used in a certain electrostatic precipitator is composed of double H shaped steel limbs and the stiffened connecting web by weld. As the width of connecting web usually exceeds 3 times of the section height of H shaped steel, the axis which connecting web lies in is the weaker axis for the stiffness of column section, while the midperpendicular of connecting web is the stronger axis. In consideration of initial geometrical imperfections and weld residual stresses, the study on stability round the stronger axis of column subjected to axial compression by nonlinear finite element method is conducted. The research results indicate that the column doesn’t present the flexural buckling round the stronger axis, but present the elasto-plastic flexural-torsional buckling. A buckling factor is produced to measure the stability performance of column round stronger axis. When the connecting channel shaped steels between two limbs and the stiffeners located on connecting web are strengthened, the buckling factor increases slightly. When the width-thickness ratio of connecting web increases, the buckling factor decreases significantly. When the slenderness of H shaped steel round the stronger axis is kept constant and the height-thickness ratio of H-shaped steel web increases, the buckling factor increases. Based on a great many computation results, the regressed recommendation is proposed how to evaluate the design buckling bearing capacity of column under axial compression round stronger axis.

NONLINEAR STABILITY ANALYSIS OF HYBRID GRID SHELLS

2013 ◽  
Vol 13 (01) ◽  
pp. 1350006 ◽  
Author(s):  
JIANGUO CAI ◽  
LEMING GU ◽  
YIXIANG XU ◽  
JIAN FENG ◽  
JIN ZHANG
Keyword(s):  
Cross Section ◽  
Failure Load ◽  
Structural Parameters ◽  
Hybrid Structure ◽  
Steel Beams ◽  
Nonlinear Stability Analysis ◽  
Plastic Buckling ◽  
Stability Performance ◽  
Hybrid Grid ◽  
The Stability

In this paper, we investigate the buckling capacity of a hybrid grid shell, which is made of quadrangular meshes diagonally stiffened by pre-tensioned thin cables. The eigenvalue buckling, geometrical nonlinear elastic buckling and elasto-plastic buckling analyses of the hybrid structure were carried out. Then the influences of the shape and scale of imperfections on the elasto-plastic buckling loads were discussed. Also, the effects of different structural parameters, such as the rise-to-span ratio, cross-section of beams, area and pre-stress of cables and boundary conditions, on the failure load were investigated. The results show that the buckling capacity is reduced when taking into account the material nonlinearity. Furthermore, the hybrid structure is highly imperfection sensitive and the reduction of the failure load due to imperfections can be considerable. The proper shape and scale of the imperfection are also important. It is also shown that there exists an optimal rise-to-span ratio resulting in a relatively high buckling capacity for a specific span. Moreover, the enlarging of the cross-section of steel beams notably improves the stability performance of the structure. However, the area and pre-stress of cables pose small effect on the structural stability.

Elastic Stability of Cylindrical Shells under Axial and Lateral Loads

1964 ◽  
Vol 68 (647) ◽  
pp. 773-775 ◽  
Author(s):  
C. Lakshmikantham ◽  
George Gerard
Keyword(s):  
Axial Compression ◽  
Present Report ◽  
Compressive Loading ◽  
Elastic Stability ◽  
External Pressure ◽  
Point Of View ◽  
Combined Loading ◽  
External Loading ◽  
Lateral Loads ◽  
The Stability

In the stability analysis of cylinders under external loading, the axial compression and lateral pressure cases are relatively well established: see, for example, ref. 1. However, from a design point of view, a biaxial system of forces due to a combination of axial compression and external pressure is often encountered in launch vehicle structures. While many other combined loading cases have appeared in the literature, the case under present consideration has not; therefore, this note is devoted to a general treatment of this problem. It is to be noted that Radhakrishnan presented some specific results for this loading combination for elastic and plastic buckling.Using the Donnell equation for small deformations, the present report considers the effect of various compressive loading combinations on the stability problem of an un-stiffened circular cylinder.

Buckling of Circular Cylindrical Shells Using a Displacement Function

1974 ◽  
Vol 96 (4) ◽  
pp. 1322-1327
Author(s):  
Shun Cheng ◽  
C. K. Chang
Keyword(s):  
Boundary Conditions ◽  
Axial Compression ◽  
Cylindrical Shells ◽  
External Pressure ◽  
Displacement Function ◽  
Combined Loading ◽  
Trial Solution ◽  
Governing Differential Equation ◽  
Circular Cylindrical Shells ◽  
The Stability

The buckling problem of circular cylindrical shells under axial compression, external pressure, and torsion is investigated using a displacement function φ. A governing differential equation for the stability of thin cylindrical shells under combined loading of axial compression, external pressure, and torsion is derived. A method for the solutions of this equation is also presented. The advantage in using the present equation over the customary three differential equations for displacements is that only one trial solution is needed in solving the buckling problems as shown in the paper. Four possible combinations of boundary conditions for a simply supported edge are treated. The case of a cylinder under axial compression is carried out in detail. For two types of simple supported boundary conditions, SS1 and SS2, the minimum critical axial buckling stress is found to be 43.5 percent of the well-known classical value Eh/R3(1−ν2) against the 50 percent of the classical value presently known.

scholarly journals The effect of flexural–torsional buckling on the stability of timber members: a case study

2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Osama A. B. Hassan
Keyword(s):  
Axial Compression ◽  
Bending Moment ◽  
List Type ◽  
Torsional Buckling ◽  
Solution Methods ◽  
Simplified Solution ◽  
The Stability ◽  
Flexural Torsional Buckling ◽  
Building Engineering

Abstract This study investigates the stability of timber members subjected to simultaneously acting axial compression and bending moment, with possible risk for torsional and flexural–torsional buckling. This situation can occur in laterally supported members where one side of the member is braced but the other side is unbraced. In this case, the free side will buckle out of plane while the braced side will be prevented from torsional and flexural–torsional buckling. This problem can be evident for long members in timber-frame structures, which are subjected to high axial compression combined with bending moments in which the member is not sufficiently braced at both sides. This study is based on the design requirement stated in Eurocode 5. Solution methods discussed in this paper can be of interest within the framework of structural and building Engineering practices and education in which the stability of structural elements is investigated. Article Highlights This case study investigates some design situations where the timber member is not sufficiently braced. In this case, a stability problem associated with combined torsional buckling and flexural buckling can arise. The study shows that the torsional and/or flexural–torsional buckling of timber members can be important to control in order to fulfil the criteria of the stability of the member according to Eurocode 5 and help the structural engineer to achieve safer designs. The study investigates also a simplified solution to check the effect of flexural torsional buckling of laterally braced timber members.

scholarly journals The elastic stability of an annular plate

1924 ◽  
Vol 106 (737) ◽  
pp. 268-284 ◽  
Keyword(s):  
Annular Plate ◽  
Practical Interest ◽  
Middle Surface ◽  
Elastic Stability ◽  
Thin Plates ◽  
Thin Shells ◽  
Stability Equation ◽  
Inner Radius ◽  
Plane Plate ◽  
The Stability

1. Introduction and Summary. —This paper deals with the elastic stability of a circular annular plate under uniform shearing forces applied at its edges. Investigations of the stability of plane plates are altogether simpler than those necessary in the case of curved plates or shells. In the first place, as shown by Mr. R. V. Southwell, two of the three equations of stability relate to a mode of instability that is not of practical interest, and are entirely independent of the third equation which gives the ordinary mode of instability resulting in the familiar bending of the middle surface of the plate. Consequently with a plane plate there is only one equation of stability to be solved, as contrasted with the case of a shell where the three equations are dependent, and must all be solved. In the second place the theory of thin shells can be used with confidence in a plane plate problem, though a more laborious procedure is necessary to deal adequately with a shell. The only stability equation required for the annular plate is therefore deduced without trouble from the theory of thin shells, and its solution presents no difficulty in the case of uniform shearing forces. A numerical discussion is given of the stability of the plate under such forces, the “favourite type of distortion” and the stess that will produce it being obtained for plates with clamped edges in wich the ratio of the outer to the inner radius exceeds 3·2. To some extent to results have been checked by experiment, in which part of the work the viter is indebted to Prof. G. I. Taylor for his valuable help and advice. Distrtion of the type predicted by the theory took place in the two thin plates of rober different ratio of radii, which were used. The disposition of the loci of points which undergo maximum normal displace nt gives some idea of the appearance of the plate after distortion has taken pce. The points have been calculated for a plate in which the ratio of radii 4·18, and the loci are shown on a diagram, which may be compared with a potograph of a distorted plate in which this ratio is 4·3. The ratio of normal dplacements of points of the plate can be seen from contours drawn on the ne diagram. (See pp. 280, 281.)

Low Buckling Loads of Axially Compressed Conical Shells

1970 ◽  
Vol 37 (2) ◽  
pp. 384-392 ◽  
Author(s):  
M. Baruch ◽  
O. Harari ◽  
J. Singer
Keyword(s):  
Boundary Conditions ◽  
Axial Compression ◽  
Plane Boundary ◽  
Essential Difference ◽  
Physical Reason ◽  
Buckling Loads ◽  
Conical Shells ◽  
Simple Supports ◽  
Interaction Curves ◽  
The Stability

The stability of simply supported conical shells under axial compression is investigated for 4 different sets of in-plane boundary conditions with a linear Donnell-type theory. The first two stability equations are solved by the assumed displacement, while the third is solved by a Galerkin procedure. The boundary conditions are satisfied with 4 unknown coefficients in the expression for u and v. Both circumferential and axial restraints are found to be of primary importance. Buckling loads about half the “classical” ones are obtained for all but the stiffest simple supports SS4 (v = u = 0). Except for short shells, the effects do not depend on the length of the shell. The physical reason for the low buckling loads in the SS3 case is explained and the essential difference between cylinder and cone in this case is discussed. Buckling under combined axial compression and external or internal pressure is studied and interaction curves have been calculated for the 4 sets of in-plane boundary conditions.

A characteristic type of instability in the large deflexions of elastic plates III. Curved rectangular plates in axial compression

1954 ◽  
Vol 222 (1148) ◽  
pp. 44-59 ◽  
Keyword(s):  
Axial Compression ◽  
Rectangular Plates ◽  
Bending Moments ◽  
Elastic Plates ◽  
Characteristic Type ◽  
Circular Tubes ◽  
Axis Parallel ◽  
Post Buckling ◽  
Thin Walled ◽  
The Stability

The analysis of part I is extended to deal with the case of free-edged rectangular plates having an initial curvature about an axis parallel to one pair of opposite edges and loaded by distributed bending moments applied to the straight edges and compressive forces applied to the curved edges. In particular, the stability and post-buckling behaviour of such plates subjected to the compressive forces alone is studied. The axially symmetrical buckling of thin-walled circular tubes in axial compression is also considered. Experimental plates are found to buckle at loads rather lower than those predicted.

The effect of finite deformations in the elastic stability of plane frames

1962 ◽  
Vol 266 (1324) ◽  
pp. 47-67 ◽  
Keyword(s):  
Critical Load ◽  
Failure Load ◽  
Elastic Stability ◽  
Load Level ◽  
Load Factor ◽  
Proportional Loading ◽  
Arbitrary Load ◽  
Plane Frames ◽  
The Difference ◽  
Rigid Joints

The circumstances are discussed under which orthogonal relations exist between the elastic critical modes of plane frames subjected to proportional loading. Orthogonal relations may be obtained provided the loading does not produce any components of deformation associated with any of the critical modes at arbitrary levels of the load factor, and provided no part of the structure remains statically indeterminate due to bar forces when all rigid joints are replaced by pin joints. When at arbitrary load factors, the structure deforms with components associated with any of the buckling modes, the elastic failure load is not identical with the lowest elastic critical load, although for many frames the two loads may be very close. A general expression is obtained which reveals the relation between the deformations at an arbitrary load level and the deflexions given by linear analysis. The difference between the elastic failure load and the elastic critical load is discussed, and an approximate treatment applicable to certain types of frame and associated loading is developed.

Experimental Study on the Stability Performance and Turning Motion of Multi-Connection VAWT

2021 ◽  
Author(s):  
Saika Iwamatsu ◽  
Yasunori Nihei ◽  
Kazuhiro Iijima ◽  
Tomoki Ikoma ◽  
Tomoki Komori
Keyword(s):  
Scaling Law ◽  
Type A ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Water Tank ◽  
Type B ◽  
Floating Bodies ◽  
Stability Performance ◽  
Turning Motion ◽  
The Stability

Abstract In this study, a series of dedicated water tank tests were conducted in wind and waves to investigate the stability performance and turning motion of Floating Offshore Wind Turbine (FOWT) equipped with two vertical axis wind turbines (VAWT). The FOWT targeted in this study is called Multi-connection VAWT, which is a new type of FOWT moored by Single-Point-Mooring (SPM) system. We designed and manufactured two types of semi-submersible floating bodies. One is a type in which VAWTs are mounted in two places of a right-angled isosceles triangle (Type-A) on a single floater, and the other is two independent units equipped with VAWTs on two separate floaters centered on a moored body. This is a type in which two semi-submersible floating bodies are lined up in a straight line (Type-B). The experimental conditions were determined by scaling down to 1/100 using Froude’s scaling law based on a wind thrust load of 320 kN (rated wind speed of 12 m/s) assuming an actual machine. In the free yawing test in waves, Type-A turned downwards, while Type-B was barely affected by the waves. Furthermore, in the free yawing test in wind, both Type-A and Type-B turned leeward and stabilized at a final point where the wind load was balanced.

Sign in / Sign up

Export Citation Format

Share Document