ممكن مساعده

noor ihsan

عضو جديد
إنضم
31 أكتوبر 2009
المشاركات
71
مجموع الإعجابات
0
النقاط
0
السلام عليكم
بس ممكن الترجمه بس ماريد ترجمه حرفيه وانما المضمون
2-1 Beam Theory
A beam is one-dimensional structure element that can sustain transverse loads by the development of bending, twisting and shearing resistances in the transverse section of the beam. A well-known formula ( ) has been derived for the bending of thin beams subjected to transverse distributed load (q) (per unit length). The modifications to the classical theory of beams (Euler- Bernoulli) have started with works of Timoshenko in 1921 on the vibration problem of prismatic bars [3].
The normal lines to the middle plan are allowed to rotate independently of the rotations (or slopes) of the middle plane. Thus, the transverse shearing deformations are considered. This improvement to the classical beam theory has helped to solve problems of deep beams by the approaches of strength of materials. New Higher – order theories for beams have been presented by many investigator; LO, K.H. Christensen, Kant in 1982, Levinson, and Hinton in 1987. these Higher – order theories are difficult and computationally more demanding, because, with each additional power of the thickness coordinate, an additional dependent unknown is introduced into the theory.
These theories require arbitrary corrections to the transverse shearing stiffness to account for the inconsistency that the transverse shearing stresses do not satisfy the conditions of zero transverse shearing stresses on the top and bottom surface of the structural element [3].
 

مواضيع مماثلة

أعلى