Pmm Journal of Applied Mathematics and Mechanics最新文献_第5页

Modelling of the elastoplastic dynamics of longitudinally reinforced wall beams based on a time-explicit central difference method 基于时间显式中心差分法的纵向加固墙梁弹塑性动力学建模

Pmm Journal of Applied Mathematics and Mechanics Pub Date : 2017-01-01 DOI: 10.1016/j.jappmathmech.2017.07.005

A.P. Yankovskii

{"title":"Modelling of the elastoplastic dynamics of longitudinally reinforced wall beams based on a time-explicit central difference method","authors":"A.P. Yankovskii","doi":"10.1016/j.jappmathmech.2017.07.005","DOIUrl":"10.1016/j.jappmathmech.2017.07.005","url":null,"abstract":"<div><p><span><span>A numerical analytical method for modelling the elastoplastic deformation of longitudinally reinforced wall beams with isotropically strengthened composite component materials, which enables a solution of the corresponding elastoplastic problem to be obtained at discrete instants of time using an explicit scheme, is developed by a time step method involving central finite differences. In the case of linear elastic composite component materials in the reinforced beams, the proposed model reduces to Bolotin's well-known structural model of the mechanics of composites. An initial-boundary-value problem of the dynamic deformation of longitudinally reinforced flexible wall beams is formulated in the von Karman approximation with consideration of their weakened resistance to transverse </span>shearing. Equations and relations corresponding to two versions of Timoshenko's theory are obtained from a few positions. An explicit “cross” scheme for numerical integration of the initial-boundary-value problem posed, which is consistent with the step-by-step scheme used to model the elastoplastic deformation of a composite beam material, is constructed. Calculations of the dynamic and quasistatic </span>bending behaviour of reinforced wall beams during the linear elastic and elastoplastic deformation of the composite component materials are performed. It is found that the classical theory is totally unacceptable for performing such calculations (except for beams of very small relative height) and that the first version of Timoshenko's theory gives adequate results only in the case of linear elastic composite component materials. Use of the second version of Timoshenko's theory is recommended as more accurate for calculations of the elastoplastic deformation of reinforced wall beams.</p></div>","PeriodicalId":49686,"journal":{"name":"Pmm Journal of Applied Mathematics and Mechanics","volume":"81 1","pages":"Pages 36-51"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.jappmathmech.2017.07.005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89170312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Contact problem for a hollow cylinder 空心圆筒的接触问题

Pmm Journal of Applied Mathematics and Mechanics Pub Date : 2017-01-01 DOI: 10.1016/J.JAPPMATHMECH.2018.03.020

D. Pozharskii

引用次数: 2

Numerical-analytical method for investigating the stability of motion of bodies of revolution in soft soil media 软土介质中旋转体运动稳定性研究的数值解析方法

Pmm Journal of Applied Mathematics and Mechanics Pub Date : 2017-01-01 DOI: 10.1016/J.JAPPMATHMECH.2018.03.016

V. Bazhenov, V. Kotov

引用次数: 0

Steady rotations of a satellite with internal elastic and dissipative forces 具有内部弹性和耗散力的卫星的稳定旋转

Pmm Journal of Applied Mathematics and Mechanics Pub Date : 2017-01-01 DOI: 10.1016/j.jappmathmech.2018.03.011

N.I. Amelkin, V.V. Kholoshchak

引用次数: 4

An equilibrium internal transverse crack in a composite elastic half-plane 复合材料弹性半平面内平衡横向裂纹

Pmm Journal of Applied Mathematics and Mechanics Pub Date : 2017-01-01 DOI: 10.1016/j.jappmathmech.2017.08.016

E.V. Rashidova, B.V. Sobol

引用次数: 5

The stability of serpentization due to the water flow in a kimberlite pipe 金伯利岩管中水流作用下蛇形化的稳定性

Pmm Journal of Applied Mathematics and Mechanics Pub Date : 2017-01-01 DOI: 10.1016/j.jappmathmech.2017.08.012

A.A. Afanasyev, E.A. Belyaeva

{"title":"The stability of serpentization due to the water flow in a kimberlite pipe","authors":"A.A. Afanasyev, E.A. Belyaeva","doi":"10.1016/j.jappmathmech.2017.08.012","DOIUrl":"10.1016/j.jappmathmech.2017.08.012","url":null,"abstract":"<div><p>A linear analysis of the stability of the course of serpentization, that is, of the exothermic hydration reaction, due to the flow of water in a kimberlite pipe is carried out, taking both the heat conduction<span> and the convective heat transfer by the fluid saturating the pipe rocks into account. It is shown that two different serpentization processes exist: a homogeneous process and an inhomogeneous process associated with a loss of stability by the homogeneous process and a non-uniform reaction rate distribution. Dimensionless similarity parameters that determine the course of the reaction are proposed. It is shown that convective heat transfer promotes a stabilization of the flow and the formation of a homogeneous serpentinite distribution. Other conditions being equal, an increase in the convective heat flux leads to an increase in the wavelengths of the unstable perturbations and to a decrease in their amplitude. A critical value of the flow rate exists, and, when this is exceeded, instability does not develop and serpentinization takes place under homogeneous conditions.</span></p></div>","PeriodicalId":49686,"journal":{"name":"Pmm Journal of Applied Mathematics and Mechanics","volume":"81 3","pages":"Pages 206-213"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.jappmathmech.2017.08.012","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82777734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Wave scattering in the joint of a straight and a periodic waveguide 直波导和周期波导结合部的波散射

Pmm Journal of Applied Mathematics and Mechanics Pub Date : 2017-01-01 DOI: 10.1016/j.jappmathmech.2017.08.006

S.A. Nazarov

引用次数: 1

The solution of a certain class of dual integral equations with the right-hand side in the form of a Fourier series and its application to the solution of contact problems for inhomogeneous media 一类右手边为傅里叶级数的对偶积分方程的解及其在非齐次介质接触问题中的应用

Pmm Journal of Applied Mathematics and Mechanics Pub Date : 2017-01-01 DOI: 10.1016/J.JAPPMATHMECH.2018.03.018

S. Aizikovich, S. Volkov, B. Mitrin

引用次数: 3

Mass loss and light curve of a large meteoroid. Analytical solution 大型流星体的质量损失和光曲线。分析解决方案

Pmm Journal of Applied Mathematics and Mechanics Pub Date : 2017-01-01 DOI: 10.1016/j.jappmathmech.2018.03.008

I.G. Brykina, G.A. Tirskiy

{"title":"Mass loss and light curve of a large meteoroid. Analytical solution","authors":"I.G. Brykina, G.A. Tirskiy","doi":"10.1016/j.jappmathmech.2018.03.008","DOIUrl":"10.1016/j.jappmathmech.2018.03.008","url":null,"abstract":"<div><p><span><span>The interaction of a large meteoroid with the Earth's atmosphere is considered in the case when it moves as a single body and when it moves as a cloud of fragments with a common shock wave. Using the literature data, an expression has been obtained for the radiative heat transfer coefficient per unit area of the </span>midsection<span><span> of a meteoroid modelled by an oblate spheroid<span><span> as a function of its velocity, size, the atmospheric density, and its oblateness<span> coefficient. The regions of predominant influence of the convective and radiative fluxes are estimated. An expression is obtained for the drag coefficient of a </span></span>spheroid. Assuming that the mass of the meteoroid decreases faster than its velocity, analytical solutions of equations of the physical theory of meteors have been obtained for the mass loss of a meteoroid of </span></span>spheroidal<span> shape, the profile of the light curve, and the altitude at which the maximum of this curve is reached. The fragmentation model, which considers the meteoroid as a cloud of fragments with the spaces between them filled by a vapour, expanding in the lateral directions and flattening in the flight direction with a rate that depends on the degree of expansion is proposed. Using this model and the analytical solutions obtained, the interaction of the Chelyabinsk meteoroid with the atmosphere is considered. Good agreement between the found solution for the profile of the light curve and the observed data–light curves based on different video recordings–is demonstrated down to an altitude of 27</span></span></span> <!-->km.</p></div>","PeriodicalId":49686,"journal":{"name":"Pmm Journal of Applied Mathematics and Mechanics","volume":"81 5","pages":"Pages 395-408"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.jappmathmech.2018.03.008","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82229187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

The evolution of the motions of a rigid body close to the Lagrange case under the action of an unsteady torque 在非定常转矩作用下，接近拉格朗日情形下刚体运动的演化

Pmm Journal of Applied Mathematics and Mechanics Pub Date : 2017-01-01 DOI: 10.1016/j.jappmathmech.2017.08.001

L.D. Akulenko , YA.S. Zinkevich , T.A. Kozachenko , D.D. Leshchenko

引用次数: 20