Instability and pillar burst mechanism in roof-pillar system with rock beam embedded in elastic foundation

Author(s):  
Xinrong Wang ◽  
Kai Guan ◽  
Jie Liu ◽  
Xige Liu
Keyword(s):  
1983 ◽  
Vol 11 (1) ◽  
pp. 3-19
Author(s):  
T. Akasaka ◽  
S. Yamazaki ◽  
K. Asano

Abstract The buckled wave length and the critical in-plane bending moment of laminated long composite strips of cord-reinforced rubber sheets on an elastic foundation is analyzed by Galerkin's method, with consideration of interlaminar shear deformation. An approximate formula for the wave length is given in terms of cord angle, elastic moduli of the constituent rubber and steel cord, and several structural dimensions. The calculated wave length for a 165SR13 automobile tire with steel breakers (belts) was very close to experimental results. An additional study was then conducted on the post-buckling behavior of a laminated biased composite beam on an elastic foundation. This beam is subjected to axial compression. The calculated relationship between the buckled wave rise and the compressive membrane force also agreed well with experimental results.


1991 ◽  
Vol 19 (3) ◽  
pp. 142-162 ◽  
Author(s):  
D. S. Stutts ◽  
W. Soedel ◽  
S. K. Jha

Abstract When measuring bearing forces of the tire-wheel assembly during drum tests, it was found that beyond certain speeds, the horizontal force variations or so-called fore-aft forces were larger than the force variations in the vertical direction. The explanation of this phenomenon is still somewhat an open question. One of the hypothetical models argues in favor of torsional oscillations caused by a changing rolling radius. But it appears that there is a simpler answer. In this paper, a mathematical model of a tire consisting of a rigid tread ring connected to a freely rotating wheel or hub through an elastic foundation which has radial and torsional stiffness was developed. This model shows that an unbalanced mass on the tread ring will cause an oscillatory rolling motion of the tread ring on the drum which is superimposed on the nominal rolling. This will indeed result in larger fore-aft than vertical force variations beyond certain speeds, which are a function of run-out. The rolling motion is in a certain sense a torsional oscillation, but postulation of a changing rolling radius is not necessary for its creation. The model also shows the limitation on balancing the tire-wheel assembly at the wheel rim if the unbalance occurs at the tread band.


2020 ◽  
Vol 91 (5) ◽  
pp. 70-76
Author(s):  
E.V. LEONTIEV ◽  
◽  

The paper considers the system "beam - elastic foundation", in which a beam with free edges was at first on a solid elastic foundation, but when a defect suddenly forms in the foundation under the right side of the beam, part of foundation was removed from design model. As a result of calculations performed by the method of initial parameters, the displacements and internal forces for the static problem are determined. The dynamic problem of determining the forces and displacements was solved, taking into account the three vibration loads F (t) = F sinγt applied at arbitrary points d when the conditions for supporting the right side of the beam on an elastic foundation were changed, the values of the dynamics coefficients were determined. Conditions are formulated that must be taken into account when analyzing the dynamic behavior of a structure under the influence of vibration loads in the case of a change in the conditions of bearing on an elastic foundation.


Author(s):  
T. Chen ◽  
C. M. Harvey ◽  
S. Wang ◽  
V. V. Silberschmidt

AbstractDouble-cantilever beams (DCBs) are widely used to study mode-I fracture behavior and to measure mode-I fracture toughness under quasi-static loads. Recently, the authors have developed analytical solutions for DCBs under dynamic loads with consideration of structural vibration and wave propagation. There are two methods of beam-theory-based data reduction to determine the energy release rate: (i) using an effective built-in boundary condition at the crack tip, and (ii) employing an elastic foundation to model the uncracked interface of the DCB. In this letter, analytical corrections for a crack-tip rotation of DCBs under quasi-static and dynamic loads are presented, afforded by combining both these data-reduction methods and the authors’ recent analytical solutions for each. Convenient and easy-to-use analytical corrections for DCB tests are obtained, which avoid the complexity and difficulty of the elastic foundation approach, and the need for multiple experimental measurements of DCB compliance and crack length. The corrections are, to the best of the authors’ knowledge, completely new. Verification cases based on numerical simulation are presented to demonstrate the utility of the corrections.


2002 ◽  
Vol 7 (3) ◽  
pp. 275-286
Author(s):  
Ahmet Birinci ◽  
Mehmet Çakıroğlu ◽  
Ragıp Erdöl
Keyword(s):  

1977 ◽  
Vol 44 (3) ◽  
pp. 509-511 ◽  
Author(s):  
P. K. Ghosh

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.


Sign in / Sign up

Export Citation Format

Share Document