Search results for "kimmoisuus"

On modelling and stability of axially moving viscoelastic materials

2013

Анализ и оптимизация устойчивости балок на сплошном упругом основании часть I (балки конечной длины) [Analysis and optimization of a beam on elastic …

2017

Problems of defining the optimal (against buckling) cross section area distribution for beams interacting with elastic foundation are considered. The stability of limited pinned beams and infinite continuous beams is analyzed. For all beams under consideration, the stability analysis is performed as for constant as for variable distributions of strength beam characteristics. The critical length is determined and the variational statement of beam stability problems is presented for this beam type. The exact solution of optimal problem is presented in the case of linear dependence of limited beam bending hardness on beam cross section area. For the case of squared and cubic dependences, the n…

Анализ и оптимизация устойчивости балок на сплошном упругом основании часть II (бесконечные балки) [Analysis and optimization of a beam on elastic fo…

2017

Problems of defining of optimal (against buckling) cross section area distribution for beams interacting with elastic foundation are considered. The stability of limited pinned beams and infinite continuous beams is analyzed. For all beams under consideration, the stability analysis is performed as for constant as for variable distributions of strength beam characteristics. The critical length is determined and the variational statement of beam stability problems is presented for this beam type. For infinite continuous beams, the stability problems are investigated as for constant as for periodic distribution of strength characteristics. In the second case, the analysis of infinite beam can…

On displacement-velocity coupling and the origin of in-plane stress in orthotropic moving continua

2014

In this paper, we address the problem of the origin of in-plane stresses in continuous, two-dimensional high-speed webs. In the case of thin, slender webs, a typical modeling approach is the application of a stationary in-plane model, without considering the effects of in-plane velocity field. However, for high-speed webs this approach is insufficient, because it neglects the coupling between the total material velocity and the deformation experienced by the material. By using a mixed Lagrange–Euler approach in model derivation, the solid continuum problem can be transformed to solid a continuum flow problem. Mass conservation in the flow problem, and the behaviour of free edges in the two-dime…

Added-Mass Based Efficient Fluid–Structure Interaction Model for Dynamics of Axially Moving Panels with Thermal Expansion

2020

The paper considers the analysis of a traveling panel, submerged in axially flowing fluid. In order to accurately model the dynamics and stability of a lightweight moving material, the interaction between the material and the surrounding air must be taken into account. The lightweight material leads to the inertial contribution of the surrounding air to the acceleration of the panel becoming significant. This formulation is novel and the case complements our previous studies on the field. The approach described in this paper allows for an efficient semi-analytical solution, where the reaction pressure of the fluid flow is analytically represented by an added-mass model in terms of the panel…

Achilles tendon viscoelastic properties and mechanical responses to a single bout of exercise

2014

Investigation of the elastic and inelastic scattering of 4He from 11B in the energy range 29-50.5 MeV

2018

We have measured the angular distributions for the elastic and inelastic scattering of 4He from 11B in the isochronous cyclotron U-150 M INP RK. The extracted α-particles beam has been accelerated to energy 29 MeV and then directed to 11B target. The experimental results were analyzed within the framework of both the optical model using different complex potential and the double folding potential obtained with different density-dependent NN interactions which give the corresponding values of the nuclear incompressibility K in the Hartree-Fock calculation of nuclear matter. peerReviewed

Kuudesluokkalaisten nuorten temperamentin, akateemisen kimmoisuuden ja koulustressin väliset yhteydet

2016

Tässä tutkimuksessa tarkasteltiin kuudesluokkalaisten nuorten temperamentin, akateemisen kimmoisuuden ja koulustressin välisiä yhteyksiä lukuvuoden aikana. Tutkimus on osa TIKAPUU - Alakoulusta yläkouluun -tutkimushanketta, johon osallistuu noin 800 keskisuomalaista nuorta. Tutkimuksessa selvitettiin, vaikuttaako oppilaan akateeminen kimmoisuus eli uskomus siitä, että hän kykenee selviytymään menestyksekkäästi koulunkäyntiin liittyvistä haasteista ja vastoinkäymisistä, hänen koulustressin kokemukseensa ja sen muutokseen lukuvuoden aikana. Tutkimuksessa tarkasteltiin myös temperamentin negatiivisen affektiivisuuden ja tahdonalaisen itsesäätelyn yhteyksiä koulustressiin ja sen muutokseen. Vii…

Modeling the mechanical behavior of carbon nanostructures

2016

Low-dimensional nanostructures are expected to have vast number of applications in the future. Particularly large amount of research has been invested in the atomthick carbon membrane called graphene, which has become popular due to its unique electronic and mechanical properties. This thesis presents studies of the mechanical and electromechanical properties of several different types of graphene nanostructures. In addition, short detours are performed in order to study the elasticity of gold nanostructures and topology effects in graphene nanoribbons. The research is performed by using several different simulation methods. In simulations the system parameters and environment can be chosen…

Variational principle and bifurcations in stability analysis of panels

2014

In this paper, the stability of a simply supported axially moving elastic panel is considered. A complex variable technique and bifurcation theory are applied. As a result, variational equations and a variational principle are derived. Anal- ysis of the variational principle allows the study of qualitative properties of the bifurcation points. Asymptotic behaviour in a small neighbourhood around an arbitrary bifurcation point is analyzed and presented. It is shown analytically that the eigenvalue curves in the (ω, V0) plane cross both the ω and V0 axes perpendicularly. It is also shown that near each bifur- cation point, the dependence ω(V0) for each mode approximately follows the shape of …