筋的截面形状对薄壁结构振动疲劳性能的影响  

Effects of Stiffeners' Cross Section Shape on Thin Walled Structures' Vibration Fatigue Property

作　　者：刘双燕[1] 涂玉倩 苗应刚[1] 李玉龙[1] 

机构地区：[1]西北工业大学航空学院,西安710072

出　　处：《航空工程进展》2017年第2期190-198,共9页Advances in Aeronautical Science and Engineering

基　　金：陕西省科技研究发展攻关计划(2009K01-39;2012GY2-26)

摘　　要：筋条的截面形状对薄壁结构的振动疲劳性能具有重要影响。对L型和T型加筋薄板进行振动试验,研究固支条件下L型筋和T型筋对薄板频率和振动疲劳寿命的影响,并从理论角度分析其原因;利用MSC有限元软件研究在正弦分布载荷下六种不同截面形状(矩形、L型、T型、I型、Z型、∏型)的筋条在给定边界条件(固支、简支)下,对薄板的频率、应力和振动疲劳寿命的影响,并对加筋板的寿命进行预测。结果表明:六种加筋构型中,Z型加筋板的第一阶固有频率最大,加筋板Von Mises应力最大点出现在同样的位置;固支条件下,加筋板的破坏位置在板的左右两侧,Z型加筋板寿命最长;简支条件下,破坏位置出现在板的中央,L型加筋板的寿命最长。Stiffeners＇ cross section shape plays an important role on the vibration fatigue property of stiffened panels. The vibration tests of two kinds of stiffened panels are carried out. The stiffened panels with L-shaped stiffener and T shaped stiffener are excited by base motion at the resonance frequency, respectively. The effects of different stiffeners＇ shape on the frequency and vibration fatigue life of thin-walled structures are studied ex- perimentally. The possible mechanism is analyzed theoretically and the test process is validated by MSC soft ware. Based on the reasonable FEM simulation, the thin-walled stiffened panels are excited by a sinusoidal dis- tributed load under two boundary conditions（fully clamped and simply supported） in MSC simulation. The effects of stiffeners with six shapes （rectangle, L-shape, T-shape, 1-shape, Z-shape and П-shape） on the frequency, stress distribution and vibration fatigue life of thin walled structures are discussed. In addition, the predicted study on the life of stiffened panel are carried out. The results show that the first natural frequency of panel with Z-shaped stiffener is the maximum among all the configurations. The peak value of the stress oc- curred at the same position. When the edges of the panel are fully clamped, the damage position occurred at the two sides of the stiffener and the fatigue life of Z-shaped stiffened panels is the longest. When the edges of the panels are simply supported, the damage position occurred at the center region of the panels and the L shaped stiffened panels had the longest life.

关 键 词：薄壁加筋结构 截面形状 固有频率 Von MISES 振动疲劳寿命 

分 类 号：V214.42[航空宇航科学与技术—航空宇航推进理论与工程] O346.2[理学—固体力学]