Author: B. F. Ruffner Publisher: ISBN: Category : Airplanes Languages : en Pages : 676
Book Description
Basic equations of Karman and Chien are solved by representing the shape of a torsion box by means of a Fourier series. Angles of twist, longitudinal stresses, and shear stresses are determined in terms of the series coefficients. The method is applied to the calculation of angles of twist and stresses in torsion boxes of rectangular, elliptical, and airfoil cross section. Results obtained for angles of twist and normal stresses are in good agreement with results of Karman and Chien except at sharp corners. Results obtained for shear stresses indicate the necessity for the use of large number of terms of the series for satisfactory accuracy.
Author: John B. Wheatley Publisher: ISBN: Category : Airplanes Languages : en Pages : 64
Book Description
Logical analysis of a box wing necessitates the allowance for the contribution of the drag spars to the torsional strength of the structure. A rigorous analysis is available in the use of the Method of Least Work. The best logical method of analysis is that applying Prandtl's Membrane Analogy. The results so obtained vary by a negligible amount from those obtained by the rigourous method. The stresses in the members of a box wing should be calculated by the membrane analogy method, but should be subject to verification by test before being used in design.
Author: Paul Kuhn Publisher: ISBN: Category : Deformations (Mechanics) Languages : en Pages : 34
Book Description
The elementary theories of bending and torsion often do not describe the stresses in aircraft shell structures with adequate accuracy; more refined stress theories have therefore have developed over a period of years. Theories of this nature are applied to the problem of calculating the deflections, particularly of wings. Bending as well as torsional deflections are discussed for wings without or with cut-outs. Whenever convenient, the formulas are given in such a form that they yield corrections to be added to the deflections calculated by means of the elementary theories. Examples show that the deflection corrections usually are quite small; very simple approximation formulas are therefore adequate for design purposes when conventional structures uder a reasonably uniform loading are being considered.
Author: George W. Zender Publisher: ISBN: Category : Airplanes Languages : en Pages : 692
Book Description
An approximate method of calculating the deformation of wings of uniform thickness having swept, M or W, Lambda, and swept-tip plan forms is presented. The method employs an adjustment to the elementary beam theory to account for the effect of the triangular root portion portion of a swept wing on the deformation of the outboard section of the wing. To demonstrate the general applicability of the method, the modified elementary theory is applied to the more comples M or W, Lambda, and swept-tip plan forms as well as to swept plan forms. For the purpose of calculating angles of attack, it is shown that the unmodified elementary beam theory applied to that part of the wing outboard of the root triangle produces satisfactory results. However, for calculating deflections it is necessary to include the effects of the root-triangle deformation.
Author: B. F. Ruffner
Author: B. F. Ruffner
Author: John B. Wheatley
Author: 
Author: United States. National Advisory Committee for Aeronautics
Author: 
Author: Paul Kuhn
Author: 
Author: George W. Zender
Author: United States. National Advisory Committee for Aeronautics