Waves in the theory of elasticity for triple porosity materials

Meccanica ◽  
2022 ◽  
Author(s):  
Andreea Arusoaie ◽  
Stan Chiriţă
Keyword(s):  
Theory Of Elasticity

Cloud computing demand elasticity algorithm based on ant colony algorithm

2020 ◽  
Vol 13 ◽  
Author(s):  
Chunyu Liu ◽  
Fengrui Mu ◽  
Weilong Zhang
Keyword(s):  
Ant Colony Algorithm ◽  
Theory Of Elasticity ◽  
Ant Colony ◽  
Demand Elasticity ◽  
Network Efficiency ◽  
Elasticity Of Demand ◽  
Operating Profit ◽  
Network Load ◽  
Network Utilization ◽  
The Impact

Background: In recent era of technology, the traditional Ant Colony Algorithm (ACO) is insufficient in solving the problem of network congestion and load balance, and network utilization. Methods: This paper proposes an improved ant colony algorithm, which considers the price factor based on the theory of elasticity of demand. The price factor is denominated in the impact on the network load which means indirect control of network load, congestion or auxiliary solution to calculate the idle resources caused by the low network utilization and reduced profits. Results: Experimental results show that the improved algorithm can balance the overall network load, extend the life of path by nearly 3 hours, greatly reduce the risk of network paralysis, and increase the profit of the manufacturer by 300 million Yuan. Conclusion: Furthermore, results shows that the improved method has a great application value in improving the network efficiency, balancing network load, prolonging network life and increasing network operating profit.

scholarly journals Towards Recognition of Scale Effects in a Solid Model of Lattices with Tensegrity-Inspired Microstructure

Solids ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 50-59
Author(s):  
Wojciech Gilewski ◽  
Anna Al Sabouni-Zawadzka
Keyword(s):  
Mechanical Properties ◽  
Continuum Model ◽  
Scale Effects ◽  
Theory Of Elasticity ◽  
Solid Model ◽  
Gradient Theory ◽  
General Description ◽  
Normal Forces ◽  
Second Gradient ◽  
Proposed Model

This paper is dedicated to the extended solid (continuum) model of tensegrity structures or lattices. Tensegrity is defined as a pin-joined truss structure with an infinitesimal mechanism stabilized by a set of self-equilibrated normal forces. The proposed model is inspired by the continuum model that matches the first gradient theory of elasticity. The extension leads to the second- or higher-order gradient formulation. General description is supplemented with examples in 2D and 3D spaces. A detailed form of material coefficients related to the first and second deformation gradients is presented. Substitute mechanical properties of the lattice are dependent on the cable-to-strut stiffness ratio and self-stress. Scale effect as well as coupling of the first and second gradient terms are identified. The extended solid model can be used for the evaluation of unusual mechanical properties of tensegrity lattices.

scholarly journals On the Thermal Stresses Due to Weathering in Natural Stones

2021 ◽  
Vol 11 (3) ◽  
pp. 1188
Author(s):  
William Hideki Ito ◽  
Talita Scussiato ◽  
Federico Vagnon ◽  
Anna Maria Ferrero ◽  
Maria Rita Migliazza ◽  
...  
Keyword(s):  
Building Materials ◽  
Thermal Stresses ◽  
Central Italy ◽  
Theory Of Elasticity ◽  
International Standards ◽  
Natural Material ◽  
Physical Weathering ◽  
Mechanism Of Degradation ◽  
Ancient Times ◽  
Natural Stones

Natural weathering is known as one of the key mechanisms causing degradation in building materials. Great efforts have been made to develop new materials and new processes for protecting those that already exist. Natural stones are an example of a natural material that has been extensively used for building construction since ancient times. In addition, they fit durability, aesthetic, and mechanical requirements. Thus, they still have great importance in the construction business nowadays. Though chemical interactions in natural stones, such as oxidation or hydrolyses, have been widely studied, in the last few decades, the physical weathering due to daily temperature variations has begun to be considered as a key mechanism of degradation and has been incorporated in international standards. This process is particularly important in calcitic marble slabs, where it can cause extensive damages to facades. Consequently, there are restrictive rules for the use of marble as an external coating material in many countries. In this paper, the thermal stresses induced by daily variations in temperature are calculated using geographic and meteorological information. The concept of sol-air temperature is used to estimate the temperatures of the hidden and exposed surfaces of a slab, and Fourier’s law and the theory of elasticity are used to calculate the temperature and stress distribution, respectively. The proposed methodology allows for a detailed reconstruction of the stress induced inside marble slabs using parameters commonly acquired in meteorological stations as input data. The developed methodology was validated by comparing in-situ measurements of the temperature of a building in Pescara (Central Italy). A good correlation between the theoretical and real temperatures was found; in particular, the peak tensile stresses inside the slabs were estimated at 75 kPa.

An inhomogeneous problem for an elastic half-strip: An exact solution

2021 ◽  
pp. 108128652199641
Author(s):  
Mikhail D Kovalenko ◽  
Irina V Menshova ◽  
Alexander P Kerzhaev ◽  
Guangming Yu
Keyword(s):  
Exact Solution ◽  
Boundary Conditions ◽  
Exact Solutions ◽  
Boundary Value Problems ◽  
Boundary Value ◽  
Theory Of Elasticity ◽  
Orthogonality Relation ◽  
Infinite Strip ◽  
Inhomogeneous Problem ◽  
Half Strip

We construct exact solutions of two inhomogeneous boundary value problems in the theory of elasticity for a half-strip with free long sides in the form of series in Papkovich–Fadle eigenfunctions: (a) the half-strip end is free and (b) the half-strip end is firmly clamped. Initially, we construct a solution of the inhomogeneous problem for an infinite strip. Subsequently, the corresponding solutions for a half-strip are added to this solution, whereby the boundary conditions at the end are satisfied. The Papkovich orthogonality relation is used to solve the inhomogeneous problem in a strip.

Stability and vibration analysis of an axially moving thin walled conical shell

2021 ◽  
pp. 107754632199760
Author(s):  
Hossein Abolhassanpour ◽  
Faramarz Ashenai Ghasemi ◽  
Majid Shahgholi ◽  
Arash Mohamadi
Keyword(s):  
Natural Frequency ◽  
Conical Shell ◽  
Shell Theory ◽  
Cone Angle ◽  
Theory Of Elasticity ◽  
Lower Velocity ◽  
Motion Equations ◽  
Conical Shells ◽  
Divergence Instability ◽  
Axially Moving

This article deals with the analysis of free vibration of an axially moving truncated conical shell. Based on the classical linear theory of elasticity, Donnell shell theory assumptions, Hamilton principle, and Galerkin method, the motion equations of axially moving truncated conical shells are derived. Then, the perturbation method is used to obtain the natural frequency of the system. One of the most important and controversial results in studies of axially moving structures is the velocity detection of critical points. Therefore, the effect of velocity on the creation of divergence instability is investigated. The other important goal in this study is to investigate the effect of the cone angle. As a novelty, our study found that increasing or decreasing the cone angle also affects the critical velocity of the structure in addition to changing the natural frequency, meaning that with increasing the cone angle, the instability occurs at a lower velocity. Also, the effect of other parameters such as aspect ratio and mechanical properties on the frequency and instability points is investigated.

scholarly journals Theory of Effective Stress in Soil and Rock and Implications for Fracturing Processes: A Review

Geosciences ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 119
Author(s):  
Vincenzo Guerriero ◽  
Stefano Mazzoli
Keyword(s):  
Porous Media ◽  
Effective Stress ◽  
Biological Tissues ◽  
Theory Of Elasticity ◽  
Past Century ◽  
Metal Powders ◽  
Science Community ◽  
Experimental Approaches ◽  
Historical Remarks ◽  
Open Issues

The effective stress principle (ESP) plays a basic role in geology and engineering problems as it is involved in fundamental issues concerning strain and failure of rock and soil, as well as of other porous materials such as concrete, metal powders, biological tissues, etc. Although since its introduction in the 1920s the main ESP aspects have been unravelled and theoretically derived, these do not appear to have been always entirely perceived by many in the science community dealing with ESP-related topics but having little familiarity with the complex theories of porous media and poroelasticity. The purpose of this review is to provide a guidance for the reader who needs an updated overview of the different theoretical and experimental approaches to the ESP and related topics over the past century, with particular reference to geological fracturing processes. We begin by illustrating, after some introductive historical remarks, the basic theory underlying the ESP, based on theory of elasticity methods. Then the different ESP-related theories and experimental results, as well as main interpretations of rock jointing and fracturing phenomena, are discussed. Two main classical works are then revisited, and a rigorous ESP proof is derived. Such a proof is aimed at geologists, engineers and geophysicists to become more familiar with theories of porous media and poroelasticity, being based on the classical theory of elasticity. The final part of this review illustrates some still open issues about faulting and hydraulic fracturing in rocks.

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