Collapse of truss core sandwich beams in 3-point bending
Collapse of truss core sandwich beams in 3-point bending
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DOI：
10.1016/s0020-7683(01)00103-2
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发表时间：
2001-09-01
影响因子：
3.6
通讯作者：
Fleck, NA
中科院分区：
文献类型：
--
作者：
Deshpande, VS;Fleck, NA
夹芯梁由桁架芯以及实心或三角形面板组成，已采用铝硅合金和硅黄铜进行熔模铸造。通过将三角形面板和四面体芯理想化为销接组件来估算其宏观有效刚度和强度；试验表明这种近似是足够的。接下来，测量这些夹芯梁在三点弯曲时的破坏响应。破坏由四种相互竞争的机制引起：面板屈服、面板起皱、压痕和芯部剪切，起作用的破坏模式取决于梁的几何形状和材料的屈服应变。根据夹芯梁面板和芯部的有效性能给出了破坏载荷的上限表达式；这些上限与测量的梁响应非常吻合，并用于构建以梁几何参数为坐标轴的破坏机制图。这些图对于为给定的结构载荷指标选择重量最小的夹芯梁是有用的。优化结果表明，桁架芯夹芯梁比具有金属泡沫芯的夹芯梁这一竞争概念要轻得多。（C）2001爱思唯尔科学有限公司。保留所有权利。
Sandwich beams, comprising a truss core and either solid or triangulated face-sheets, have been investment cast in an aluminium-silicon alloy and in silicon brass. The macroscopic effective stiffness and strength of the triangulated face-sheets and tetrahedral core are estimated by idealising them as pin-jointed assemblies; tests show that this approximation is adequate. Next, the collapse responses of these sandwich beams in 3-point bending are measured. Collapse is by four competing mechanisms: face-yield, face-wrinkling, indentation and core shear, with the active collapse mode dependent upon the beam geometry and yield strain of the material. Upper bound expressions for the collapse loads are given in terms of the effective properties of the faces and core of the sandwich beam; these upper bounds are in good agreement with the measured beam response, and are used to construct collapse mechanism maps with beam geometrical parameters as the axes. The maps are useful for selecting sandwich beams of minimum weight for a given structural load index. The optimisation reveals that truss core sandwich beams are significantly lighter than the competing concept of sandwich beams with a metallic foam core. (C) 2001 Elsevier Science Ltd. All rights reserved.