A yield displacement distribution-based approach for strength assignment to lateral force-resisting elements having strength dependent stiffness

2003 ◽  
Vol 32 (15) ◽  
pp. 2319-2351 ◽  
Author(s):  
W. K. Tso ◽  
B. Myslimaj
Keyword(s):  
Lateral Force ◽  
Displacement Distribution ◽  
Yield Displacement

On the lateral force distribution among structural walls in multistorey buildings

2002 ◽  
Vol 35 (4) ◽  
pp. 231-242 ◽  
Author(s):  
Avigdor Rutenberg ◽  
Edward Leibovich
Keyword(s):  
Shear Force ◽  
Bending Moment ◽  
Lateral Force ◽  
Force Distribution ◽  
Seismic Behaviour ◽  
Structural Walls ◽  
Mode Effects ◽  
Yield Displacement ◽  
Dynamic Amplification ◽  
Multi Mode

The seismic behaviour of regular multistorey structures supported laterally by a number of reinforced concrete cantilever walls with markedly different lengths is addressed. It is shown that the shear force distribution among the walls is strongly affected by the different yield displacement levels of the walls. The share of the shear force carried by the shorter walls is shown to be larger than their share in the bending moment. The dynamic amplification of the shear forces due to multi-mode effects and the implications for capacity design are noted. Numerical examples illustrate the problem.

Low cyclic loading tests and fatigue damage models of concrete bridge piers reinforced with high-strength rebar

2020 ◽  
pp. 136943322096174
Author(s):  
Wei-ding Zhuo ◽  
Suiwen Wu ◽  
Zhao Liu ◽  
Hua Zang
Keyword(s):  
Cyclic Loading ◽  
Fatigue Damage ◽  
High Strength ◽  
Lateral Force ◽  
Displacement Amplitude ◽  
Bridge Piers ◽  
Yield Displacement ◽  
Loading Tests ◽  
Cyclic Loading Tests ◽  
Rc Bridge Piers

Reinforced concrete bridge piers are extremely vulnerable to damage during long-duration ground excitations or main shock-aftershock type earthquakes due to accumulated damage caused by a great number of reversed excursions in elastic-plastic range. However, few studies on fatigue damage of piers can be found in literature. Low-cyclic loading tests of four identical RC bridge piers with high-strength rebar HRB600E (yield strength about 600 MPa) were carried out in this study. One of specimens was taken as the benchmark and was subjected to a conventional load protocol, and the rest was subjected to one, two and three times yield displacement, respectively. The research results showed that the fatigue strength of RC bridge piers tended to drop drastically at about ten cycles and then slowed down gently. It was found that strength degradation rate increased significantly with the displacement amplitude for fatigue tests while the fatigue life decreased dramatically with the displacement amplitude. In particular, when the cyclic loading displacement exceeded 2 times the yield displacement, the fatigue life dropped dramatically. Based on the experimental data, an exponential-type damage model was proposed with the peak lateral force at the first cycle as the coefficient, the cycle count as the base and factor of the loading displacement amplitude as the exponent, which could accurately predict the degraded lateral force of the bridge piers at different constant drifts. An accumulative fatigue damage index was established to evaluate the damage level of bridge piers.

Computer Modeling of a Tire under Cornering Loads

1989 ◽  
Vol 17 (2) ◽  
pp. 86-99 ◽  
Author(s):  
I. Gardner ◽  
M. Theves
Keyword(s):  
Finite Element Analysis ◽  
Geometric Approach ◽  
Lateral Force ◽  
Slip Angle ◽  
Element Analysis ◽  
Pressure Distributions ◽  
Slip Effects ◽  
Improved Accuracy ◽  
Nonlinear Geometric ◽  
Good Agreement

Abstract During a cornering maneuver by a vehicle, high forces are exerted on the tire's footprint and in the contact zone between the tire and the rim. To optimize the design of these components, a method is presented whereby the forces at the tire-rim interface and between the tire and roadway may be predicted using finite element analysis. The cornering tire is modeled quasi-statically using a nonlinear geometric approach, with a lateral force and a slip angle applied to the spindle of the wheel to simulate the cornering loads. These values were obtained experimentally from a force and moment machine. This procedure avoids the need for a costly dynamic analysis. Good agreement was obtained with experimental results for self-aligning torque, giving confidence in the results obtained in the tire footprint and at the rim. The model allows prediction of the geometry and of the pressure distributions in the footprint, since friction and slip effects in this area were considered. The model lends itself to further refinement for improved accuracy and additional applications.

Normalization of Tire Force and Moment Data

1993 ◽  
Vol 21 (2) ◽  
pp. 91-119 ◽  
Author(s):  
H. S. Radt ◽  
D. A. Glemming
Keyword(s):  
Surface Water ◽  
Lateral Force ◽  
Slip Angle ◽  
Inflation Pressure ◽  
Slip Ratio ◽  
Tire Force ◽  
Camber Angle ◽  
Potential Benefits ◽  
Overturning Moment ◽  
Semi Empirical

Abstract Semi-empirical theories of tire mechanics are employed to determine appropriate means to normalize forces, moments, angles, and slip ratios. Force and moment measurements on a P195/70R 14 tire were normalized to show that data at different loads could then be superimposed, yielding close to one normalized curve. Included are lateral force, self-aligning torque, and overturning moment as a function of slip angle, inclination angle, slip ratio, and combinations. It is shown that, by proper normalization of the data, one need only determine one normalized force function that applies to combinations of slip angle, camber angle, and load or slip angle, slip ratio, and load. Normalized curves are compared for the effects of inflation pressure and surface water thickness. Potential benefits as well as limitations and deficiencies of the approach are presented.

Simplified Prediction of Ply Steer in Radial Tires

1980 ◽  
Vol 8 (1) ◽  
pp. 3-9 ◽  
Author(s):  
C. W. Bert
Keyword(s):  
Composite Laminate ◽  
Ground Plane ◽  
Lateral Force ◽  
Rolling Contact ◽  
Slip Angle ◽  
Uniform Stress ◽  
Rubber Composite ◽  
Laminate Theory ◽  
Contact Models ◽  
Uniform Stress State

Abstract Ply steer is a rolling contact phenomenon which manifests itself as a lateral force acting at the ground plane of a tire constrained in yaw or a change in slip angle of a tire free to yaw. It has long been known that radial tires generally exhibit greater ply steer than do bias tires. However, the only previously published quantitative analysis of this phenomenon considered the multi-layer cord-rubber composite by means of netting analysis, which is not very accurate at cord angles typical of radial tire belts. A simple, explicit expression is developed herein by combining modern composite laminate theory with two very simple, uniform-stress-state tire-road contact models. The ply-steer results predicted by the resulting expressions are compared with some experimental results and the agreement is found to be reasonably satisfactory.

Measurement and Visualization of the Contact Pressure Distribution of Rubber Disks and Tires

1995 ◽  
Vol 23 (4) ◽  
pp. 238-255 ◽  
Author(s):  
E. H. Sakai
Keyword(s):  
Pressure Distribution ◽  
Contact Pressure ◽  
Contact Area ◽  
Light Absorption ◽  
Lateral Force ◽  
Contact Pressure Distribution ◽  
High Definition ◽  
The Road ◽  
Close Relationship ◽  
Processing Techniques

Abstract The contact conditions of a tire with the road surface have a close relationship to various properties of the tire and are among the most important characteristics in evaluating the performance of the tire. In this research, a new measurement device was developed that allows the contact stress distribution to be quantified and visualized. The measuring principle of this device is that the light absorption at the interface between an optical prism and an evenly ground or worn rubber surface is a function of contact pressure. The light absorption can be measured at a number of points on the surface to obtain the pressure distribution. Using this device, the contact pressure distribution of a rubber disk loaded against a plate was measured. It was found that the pressure distribution was not flat but varied greatly depending upon the height and diameter of the rubber disk. The variation can be explained by a “spring” effect, a “liquid” effect, and an “edge” effect of the rubber disk. Next, the measurement and image processing techniques were applied to a loaded tire. A very high definition image was obtained that displayed the true contact area, the shape of the area, and the pressure distribution from which irregular wear was easily detected. Finally, the deformation of the contact area and changes in the pressure distribution in the tread rubber block were measured when a lateral force was applied to the loaded tire.

scholarly journals One-Dimensional Lateral Force Anisotropy at the Atomic Scale in Sliding Single Molecules on a Surface

Nano Letters ◽  
2021 ◽  
Author(s):  
Yuan Zhang ◽  
Daniel J. Trainer ◽  
Badri Narayanan ◽  
Yang Li ◽  
Anh T. Ngo ◽  
...  
Keyword(s):  
Single Molecules ◽  
Lateral Force ◽  
Atomic Scale ◽  
One Dimensional

scholarly journals Ultrasensitive nano-optomechanical force sensor operated at dilution temperatures

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Francesco Fogliano ◽  
Benjamin Besga ◽  
Antoine Reigue ◽  
Laure Mercier de Lépinay ◽  
Philip Heringlake ◽  
...  
Keyword(s):  
Thermal Conduction ◽  
Photon Counting ◽  
Force Sensor ◽  
Lateral Force ◽  
Oscillation Period ◽  
The Road ◽  
Field Gradients ◽  
Concomitant Reduction ◽  
Generic Strategy ◽  
Conduction Properties

AbstractCooling down nanomechanical force probes is a generic strategy to enhance their sensitivities through the concomitant reduction of their thermal noise and mechanical damping rates. However, heat conduction becomes less efficient at low temperatures, which renders difficult to ensure and verify their proper thermalization. Here we implement optomechanical readout techniques operating in the photon counting regime to probe the dynamics of suspended silicon carbide nanowires in a dilution refrigerator. Readout of their vibrations is realized with sub-picowatt optical powers, in a situation where less than one photon is collected per oscillation period. We demonstrate their thermalization down to 32 ± 2 mK, reaching very large sensitivities for scanning probe force sensors, 40 zN Hz−1/2, with a sensitivity to lateral force field gradients in the fN m−1 range. This opens the road toward explorations of the mechanical and thermal conduction properties of nanoresonators at minimal excitation level, and to nanomechanical vectorial imaging of faint forces at dilution temperatures.

scholarly journals Influence of hinge length and distribution number on the camber and cornering properties of a non-pneumatic tire

2020 ◽  
Vol 12 (12) ◽  
pp. 168781402098468
Author(s):  
Xianbin Du ◽  
Youqun Zhao ◽  
Yijiang Ma ◽  
Hongxun Fu
Keyword(s):  
Neural Network ◽  
Network Model ◽  
Adaptive Learning ◽  
High Speed ◽  
Back Propagation ◽  
Lateral Force ◽  
Learning Ability ◽  
Vehicle Performance ◽  
Neural Network Theory ◽  
Bp Neural Network Model

The camber and cornering properties of the tire directly affect the handling stability of vehicles, especially in emergencies such as high-speed cornering and obstacle avoidance. The structural and load-bearing mode of non-pneumatic mechanical elastic (ME) wheel determine that the mechanical properties of ME wheel will change when different combinations of hinge length and distribution number are adopted. The camber and cornering properties of ME wheel with different hinge lengths and distributions were studied by combining finite element method (FEM) with neural network theory. A ME wheel back propagation (BP) neural network model was established, and the additional momentum method and adaptive learning rate method were utilized to improve BP algorithm. The learning ability and generalization ability of the network model were verified by comparing the output values with the actual input values. The camber and cornering properties of ME wheel were analyzed when the hinge length and distribution changed. The results showed the variation of lateral force and aligning torque of different wheel structures under the combined conditions, and also provided guidance for the matching of wheel and vehicle performance.

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