Related Experiment Video
Updated: Jul 7, 2026

10:36
Stress Distribution During Cold Compression of Rocks and Mineral Aggregates Using Synchrotron-based X-Ray Diffraction
Published on: May 20, 2018
Compactification of patterns by a singular convection or stress
1School of Mathematical Sciences, Tel Aviv University, Tel Aviv 69978, Israel. rosenau@post.tau.ac.il
Physical Review Letters
|February 1, 2008
Summary
Certain nonlinearities can create sharp fronts in physical systems, unlike typical smooth solutions. This research explores how specific nonlinear convection terms induce sharp front localization in dissipative and dispersive models.
Area of Science:
- Nonlinear Dynamics
- Mathematical Physics
- Partial Differential Equations
Background:
- Many physical systems exhibit propagating disturbances described by equations with smooth solutions.
- Sharp propagating fronts are often absent in these models, limiting their descriptive power for certain phenomena.
Purpose of the Study:
- To demonstrate how specific nonlinearities can induce sharp propagating fronts.
- To investigate the emergence of sharp fronts in both dissipative and dispersive systems.
Main Methods:
- Analysis of nonlinear convection terms in partial differential equations.
- Study of dissipative equations of the form u_{t}+ partial differential_{x}f(u)=u_{xx}.
- Study of dispersive equations of the form u_{t}+ partial differential_{x}f(u)+u_{xxx}=0.
Main Results:
- A weakly singular convection term f(u)=-u^{alpha}+u^{m} (0
- Sharp fronts were observed to emerge in higher-dimensional extensions and Boussinesq-type wave phenomena.
Conclusions:
- Nonlinear convection is a key mechanism for generating sharp fronts in physical systems.
- The findings have implications for understanding phenomena with abrupt transitions in various scientific domains.
Related Concept Videos
Stress Concentrations
Stress concentration is when stress intensifies near discontinuities such as holes or abrupt cross-sectional changes in a structural member. This localized stress can often surpass the average stress within the member. The stress distribution in flat bars, either with a circular hole or varying widths connected by fillets, can be determined experimentally using a photoelastic method. The results are based on ratios of geometric parameters like the ratio of the hole's radius to the smaller width...
Stress Concentrations
The concept of stress concentration is crucial for understanding how materials respond under bending stresses, particularly when there are irregularities or discontinuities in the material's geometry. Normally, stress in a symmetric member subjected to pure bending is assumed to be uniformly distributed across the entire cross-section. However, this assumption does not hold when there are variations in the cross-sectional geometry or the presence of notches and holes.
The stress concentration...
The stress concentration...
Transformation of Plane Stress
Studying stress transformation is essential in understanding how stress components within a material, like a cube under plane stress, change with rotation. This change is analyzed by considering a prismatic element within the cube. As the element rotates, the stress components acting on it—both normal and shearing stresses—change in magnitude and orientation. This change is quantified using trigonometric functions of the rotation angle, relating the forces acting on the rotated element's faces...
Stress: General Loading Conditions
To grasp the intricacy of real-world conditions where multiple loads are applied simultaneously to a structure, one might visualize a section passing through a specific point within a body, aligned parallel to the xy plane. This section is subjected to various forces, including original loads, normal forces, and shearing forces.
The shearing force, possessing potential directionality within the plane of the section, is simplified into two component forces running parallel to the x and y axes.
The shearing force, possessing potential directionality within the plane of the section, is simplified into two component forces running parallel to the x and y axes.
Components of Stress
Stress analysis under multiple loading conditions is intricate, necessitating a comprehensive grasp of normal and shearing stresses. Consider a small cube at point O, subjected to stress on all six faces, visible or not. Normal stress components σx, σy, σz act perpendicularly to the x, y, and z axes. Shearing stress components τxy and τxz are exerted on faces perpendicular to these axes.
Interestingly, the hidden cube faces also experience these stresses, equal and opposite to those on the...
Interestingly, the hidden cube faces also experience these stresses, equal and opposite to those on the...
Stress Concentrations in Circular Shafts
Consider the elastic torsion formula, which applies to a circular shaft with a consistent cross-section. This formula assumes that the shaft's ends are loaded with rigid plates firmly attached. However, in many cases, torques are applied to the shaft through mechanisms like flange couplings or gears, which are connected by keys inserted into keyways. This application method modifies the stress distribution near the point of torque application, causing it to deviate from the distributions...
