Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Vibration control of band saws: Theory and experiment (1990)
    Springer
    Wood science and technology 24 (1990), S. 355-373 
    Details
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Active vibration control is a key to the improvement of the cutting performance and productivity of band saws. In this paper a new method is presented for active control of band saw vibration. The transfer function of a closed-loop system consisting of the band saw, a feedback control law and the dynamics of the sensing and force actuation devices is derived. Analysis of the root loci of the closed-loop system gives two stability criteria. Stabilizing controller design is carried out for both collocation and dislocation of the sensors and actuators. It is found that vibration in all the modes can be damped through use of only one sensor and one actuator and that the control algorithms presented are realizable in practice. The theory presented is experimentally verified.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00227056
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Theoretical and experimental analysis of circular saw tensioning (1979)
    Springer
    Wood science and technology 13 (1979), S. 211-237 
    Details
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Tensioning is the saw prestressing procedure most commonly used in the forest products industry to increase the stability of thin circular saws. This procedure stiffens the saw blade by introducing favorable in-plane residual stresses either by local plastic deformation or by local heating. In industry today, rolling is the standard procedure for introducing such stresses. The first part of this paper is concerned with a method of tension evaluation. The method examined consists of measuring saw blade modal stiffness, and it correlates the elastic stiffness of the saw, which approximates the vibration modes, and the natural frequencies associated with these modes. The predictions of the saw frequency shift due to stiffness variations were found to agree closely with experimentally determined frequencies. The method thus offers a practical procedure for tension evaluation and could replace the currently used technique of measuring the light gap under a straightedge placed along the saw diameter. The second part of this paper theoretically analyzes the relationship between the rolling load and the resulting tensioning stresses. The procedure followed in the theoretical model determines the identation load by equating the external power of loading with the power of storing in the elastic zones and of internal dissipation in the plastic zone. The residual stresses obtained by superpositioning the stresses due to unloading were generally in good agreement with the experimentally determined tensioning stresses outside the rolled region. The theory developed can be very useful in predicting tensioning stresses for a given rolling load and roller geometry.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00350225
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Analysis of roll tensioning and its influence on circular saw stability (1983)
    Springer
    Wood science and technology 17 (1983), S. 287-302 
    Details
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary In a typical sawmill, about 12% of the wood which is cut is reduced to sawdust. Further material is lost during subsequent planing. A substantial part of this large loss of a costly natural resource can be saved by the use of thin, stable sawblades, but only if proper saw tensioning conditions are developed. The thickness of a stable sawblade can be minimized through optimal tensioning, an increasingly urgent objective because of sharply rising raw material costs. A theoretical model is presented which accurately describes the development of residual stresses in a roll tensioned circular sawblade and the resulting changes in saw critical speed. This model is essential for the reliable prediction of optimal tensioning conditions for any given saw operating state, and for the development of automated control of the tensioning process. An example is presented of an optimally tensioned circular sawblade for which a 40% thickness reduction is achieved compared with an equivalent untensioned sawblade with the same critical speed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00349916
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Origin of idling noise in circular saws and its suppression (1984)
    Springer
    Wood science and technology 18 (1984), S. 33-49 
    Details
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary This paper concerns the mechanism of noise generation and methods of noise reduction for idling circular saws. Experiments were conducted to examine the sources of saw noise. Saw resonant vibration is proven to be excited aerodynamically rather than by mechanical imbalance. The source of noise generated from a resonating saw and that generated from a nonresonating saw are shown to be identical. A mathematical model is proposed to formulate the dependence of the noise source upon saw kinematic and geometric parameters. Based upon this model and the associated experiments, several potential techniques for noise reduction through design of saw tooth geometry are recommended and discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00632129
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    A review of residual stresses and tensioning in circular saws (1974)
    Springer
    Wood science and technology 8 (1974), S. 148-161 
    Details
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary The origin and measurement of residual stresses and their effect on the transverse stability of circular saws are discussed, with emphasis placed on nondestructive stress analyses, their limits of application, and their possible adaptation to the measurement of residual stresses in circular saws. Saw stability variations can be computed once the stress distribution is known. Evaluation of the X-ray diffraction technique and the ultrasonic and magnetic methods were considered for this purpose. Alternatively, saw stability can be related to resonance and bending stiffness measurements in specific modes. However, the state of stress cannot be inferred from these tests. For saw stability prediction, measurement of the state of stress is more essential than are direct stiffness measurements.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00351369
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Global-local finite element (1971)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 3 (1971), S. 565-574 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Finite element procedures usually require more degrees of freedom for a specified accuracy than does a classical Ritz procedure if suitable coordinate functions are available. This paper develops a combined global and local dependent variable representation which couples the conventional and finite element Ritz methods. This hybrid method preserves much of the flexibility of the finite element method while increasing the solution accuracy for a specified system order. The method is illustrated by examination of a beam and a plate vibration problem.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620030410
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Derivatives and their error bounds in second order problems by finite element (1976)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 10 (1976), S. 1065-1075 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A previous paper by the authors presented a finite element technique for computing accurate and bounded solutions at arbitrary points in second order mixed boundary value problems. The technique is extended herein to the computation of accurate and bounded derivatives at arbitrary interior points. Numerical results are presented to illustrate both the strengths and limitations to the method.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620100508
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Solution of non-linear differential equations by discrete least squares (1978)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 12 (1978), S. 597-612 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A general-purpose technique has been developed for solving non-linear partial differential equations. A set of approximating functions with undetermined parameters is used to evaluate the differential equation and boundary conditions at discrete points, forming a set of residuals to be minimized. The parameters which minimize the sum of squared residuals are determined by a non-linear least-squares minimization technique. Initial value problems are solved by integrating the equations with respect to time at the fitting points by a predictor-corrector algorithm. The resulting formulation is independent of the form of the problem and the approximating functions, so that a broad class of problems may be solved with a single computer program. The technique is applied to several boundary and initial value problems in one and two spatial dimensions. The tecnique is applied to several boundary and initial value problems in one and two spatial dimensions.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620120405
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    An algorithm for the solution of a third-order eigenvalue problem (1980)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 15 (1980), S. 457-463 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A simple, rapidly convergent procedure is described for solving a third-order symmetric eigenvalue problem Au = λ Bu typically arising in vibration analysis. The eigenvalue problem is represented in terms of its variational dual, the Rayleigh quotient, and the eigenosolution is obtained through a topographical search for points of quotient stationarity. The associated computer routine is compact and can easily be incorporated within the calling program. Degenerate eigensolutions cause no difficulty. An example FORTRAN routine is given.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620150312
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Solution of non-linear boundary value problems by discrete least squares (1977)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 11 (1977), S. 641-652 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: This paper presents a new discrete (point-matching) least squares method for solving general, non-linear boundary value problems. The technique uses a mixed formulation and minimizes the sum of squared residuals by Powell's (1965) algorithm. The present method is compared with finite difference and weighted residual finite element methods in the examples and discussion. It shows considerable promise as a general differential equation solver for both large and small computer systems.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620110404
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...