含通孔损伤变截面钛合金蜂窝壁板拉伸性能研究

针对飞行器结构采用的钛合金蜂窝壁板,采用试验研究和有限元分析相结合的方法,研究了通孔损伤对变截面钛合金蜂窝壁板拉伸性能的影响。其中,有限元模型采用参数化建模方法建立,包含蜂窝芯体细节和斜角区细节结构。研究结果显示,斜角区是变截面钛合金蜂窝壁板的薄弱部位,无损伤试验件的破坏模式为沿斜角起始区域内蒙皮倒圆处横截面断裂;对于含通孔损伤的壁板,存在一个通孔损伤直径阈值(40mm),当通孔损伤直径小于阈值时,含通孔损伤壁板的破坏模式和拉伸破坏载荷与无损伤壁板一致;当通孔损伤直径超过阈值后,含通孔损伤壁板的破坏模式改变为沿通孔损伤横截面断裂,拉伸破坏载荷随着通孔损伤直径的增加而线性降低。

Effects of Penetrating Holes on Tensile Properties of Titanium Honeycomb Core Panels With Variable Cross-Section

The effects of penetrating holes on the tensile properties of titanium honeycomb panels with variable cross-section used in aircraft structure was studied experimentally and numerically.Among them,the finite element model included the details of the honeycomb core and the detailed structure of the bevel area was established by parametric modeling method.The results showed that the bevel area was the weak part of the titanium honeycomb panels with variable cross-section,the failure mode of the specimen without hole was the cross section fracture along the chamfer of the skin in the initial area of bevel.For the panels with penetrating hole,there was a diameter threshold of 40mm.When the penetrating hole diameter was less than the threshold,the failure mode and tensile fracture load of the panels with penetrating hole were consistent with the panels without hole.When the penetrating hole diameter exceeded the threshold,the failure mode of the panels with penetrating hole changed to fracture along the cross-section of penetrating hole and the tensile fracture load decreased linearly with the increase of the diameter of penetrating hole.