Author: David A. EvensenPublisher:
ISBN:
Category : Shells (Engineering)
Languages : en
Pages : 36
Book Description
Nonlinear Flexural Vibrations of Thin-walled Circular Cylinders
Author: David A. EvensenPublisher:
ISBN:
Category : Shells (Engineering)
Languages : en
Pages : 36
Book Description
Nonlinear Axisymmetric Flexural Vibration of Spherical Shells
Author: Haruo KuniedaPublisher:
ISBN:
Category : Nonlinear theories
Languages : en
Pages : 60
Book Description
Axisymmetric responses are presented of a nonshallow thin-walled spherical shell on the basis of nonlinear bending theory. An ordinary differential equation with nonlinearity of quadratic as well as cubic terms associated with variable time is derived. The derivation is based on the assumption that the deflection mode is the sum of four Legendre polynomials, and the Galerkin procedure is applied. The equation is solved by asymptotic expansion, and a first approximate solution is adopted. Unstable regions of this solution are discussed.
A Theoretical and Experimental Study of the Nonlinear Flexural Vibrations of Thin Circular Rings
Author: David A. EvensenPublisher:
ISBN:
Category : Flexure
Languages : en
Pages : 68
Book Description
The nonlinear flexural vibrations of thin circular rings are analyzed by assuming two vibration modes and then applying Galerkin's procedure on the equations of motion. This procedure results in coupled nonlinear ordinary differential equations with time as the independent variable. The applied loading is taken to be harmonic in time, and approximate solutions to the equations are obtained by the method of averaging. One such solution involves the vibration of a single bending mode; a subsequent stability analysis shows that this single-mode response is valid only for certain combinations of amplitude, nonlinear coupling causes its companion mode to respond and participate in the motion. Approximate solutions are obtained for this coupled-mode case, and their stability is examined. The steady-state response curves contain an unusual "gap", where both the one- and two-mode solutions are unstable. These results were confirmed on an analog computer, and nonsteady vibrations were observed in the gap region. An experimental study of the problem was also conducted. Theory and experiment both indicate a nonlinearity of the softening type and the appearance of the companion mode. Measurements of the steady-state response are in good agreement with the calculated values, and the experimentally determined mode shapes agree with the form of the assumed deflection. The analytical and experimental results exhibit several features that are characteristic of nonlinear vibrations of axisymmetric systems in general and of circular cylindrical shells in particular.
Scientific and Technical Aerospace Reports
Author: Monthly Catalog of United States Government Publications
Author: United States. Superintendent of DocumentsPublisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1464
Book Description
Computational Fluid and Solid Mechanics
Author: K.J. BathePublisher: Elsevier
ISBN: 0080552811
Category : Technology & Engineering
Languages : en
Pages : 975
Book Description
The MIT mission - "to bring together Industry and Academia and to nurture the next generation in computational mechanics is of great importance to reach the new level of mathematical modeling and numerical solution and to provide an exciting research environment for the next generation in computational mechanics." Mathematical modeling and numerical solution is today firmly established in science and engineering. Research conducted in almost all branches of scientific investigations and the design of systems in practically all disciplines of engineering can not be pursued effectively without, frequently, intensive analysis based on numerical computations.The world we live in has been classified by the human mind, for descriptive and analysis purposes, to consist of fluids and solids, continua and molecules; and the analyses of fluids and solids at the continuum and molecular scales have traditionally been pursued separately. Fundamentally, however, there are only molecules and particles for any material that interact on the microscopic and macroscopic scales. Therefore, to unify the analysis of physical systems and to reach a deeper understanding of the behavior of nature in scientific investigations, and of the behavior of designs in engineering endeavors, a new level of analysis is necessary. This new level of mathematical modeling and numerical solution does not merely involve the analysis of a single medium but must encompass the solution of multi-physics problems involving fluids, solids, and their interactions, involving multi-scale phenomena from the molecular to the macroscopic scales, and must include uncertainties in the given data and the solution results. Nature does not distinguish between fluids and solids and does not ever repeat itself exactly.This new level of analysis must also include, in engineering, the effective optimization of systems, and the modeling and analysis of complete life spans of engineering products, from design to fabrication, to possibly multiple repairs, to end of service.
NASA Scientific and Technical Reports
Author: United States. National Aeronautics and Space Administration Scientific and Technical Information DivisionPublisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 2300
Book Description
A Selected Listing of NASA Scientific and Technical Reports for ...
Author: United States. National Aeronautics and Space Administration. Scientific and Technical Information DivisionPublisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 2088
Book Description
A Selected Listing of NASA Scientific and Technical Reports for 1966
Author: United States. National Aeronautics and Space Administration. Scientific and Technical Information DivisionPublisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 2084
Book Description
Author: