论文部分内容阅读
一、引言机冀是飞机的重要组成部分.它的主要功用是产生升力。作用在机冀上的力主要有:空气动力,机翼上的部件的质量力,机冀本身的质量力.直机冀的外伸段是指远离根部和开口处的那一段机翼。在计算这一段机翼的正应力时,根据平面定律,棱柱体和冀肋在其自身平面内为完全刚性等假设,把机翼看作组合的悬臂梁来考虑,在自由弯曲中,如果应变(或变形)服从平剖面假设,正应力可按下式计算:σ=M_n/I_xy(1)这公式说明正应力沿y方向是成直线公布的.这时的σ-ε图是一条直线.但真实的机翼结构,虽然应变服从平剖面假设,但应力沿y方向不成直线分布,这就使得构件的应力不能直接用公式(1)来计算。本文探讨折算系数法,就是要解决这个问题。二、折算系数法图1为机冀的受力简图。为了决定任意剖面b-b内的正应力,假定该剖面在弯矩M_x的作用下相对剖面a-a的转角为β,则剖面b-b内任一构件的纵向位移为:u_1=β·y_1(2)y_1为任一构件的重心到剖面中性轴的距离。
I. INTRODUCTION Ji Ji is an important part of the aircraft and its main function is to generate lift. The main forces acting on the aircraft are: aerodynamics, the mass force of the components on the wing, the mass force of the aircraft itself, and the extension of the straight machine Ji means the wing that is far from the root and the opening. In calculating the normal stress of a wing, considering the wing as a combined cantilever, based on the assumption that the law of plane, the prismatic body and the rib are completely rigid in their own plane, in free-form bending, if the strain (Or deformation) subject to the hypothesis of flat section, normal stress can be calculated as follows: σ = M_n / I_xy (1) This formula shows the normal stress is published in a straight line along the y direction. However, the real wing structure, although the strain obeys the assumption of flat section, does not distribute the stress in a straight line in the y direction, which makes the component stress can not be directly calculated by formula (1). This article discusses the conversion coefficient method is to solve this problem. Second, the conversion factor method Figure 1 is the mechanical Ji’s stress diagram. In order to determine the normal stress in an arbitrary section bb, assuming that the angle of the section relative to the section aa is β under the bending moment M_x, the longitudinal displacement of any component in the section bb is: u_1 = β · y_1 (2) y_1 is The center of gravity of any component to the neutral axis of the section.