Transient Dynamic Response and Failure of Sandwich Composite Structures under Impact Loading with Fluid Structure Interaction

Investigation of vibrational characteristics of composite beams with fluid–structure interaction

“…That means, while the mode shape is associated with the beam deflection, the modal curvature is related to bending strain of the beam. This result supports the finding in the previous impact testing on beam and plate structures in air and water, respectively [13,14]. In the previous studies, more than a dozen strain gages were attached to a composite plate which was clamped along the edges.…”

“…Studies of polymer composites under low velocity impact have shown that there is an increase in impact force with samples tested while in contact with water due to the added mass effect with the fluid medium [12][13][14]. The studies also have shown that the natural frequencies of polymer composite plates, when in contact with water, decrease by approximately one-third of those tested in air.…”

“…However, given there is little pixel movement with the out of plane motion of the beam and the use of halogen lighting, it is reasonable to set the exposure time to 100 ls in order to achieve accurate results without any blur in the images. Testing the beam while submerged in water greatly reduces the velocity given that the frequency of vibration is reduced by approximately one third [13,14]. Therefore, the same exposure time can be set for tests in air and in water.…”

Study of composite plate traveling in water containing Ice Equivalent Objects

“…While the previous research has not considered the FSI effect, other studies [2][3][4][5] showed that the FSI effect on composite structures submerged in water reduces the critical impact loads for failure as well as the number of cycles for failure to occur. In addition, FSI may change vibrational mode shapes, which can result in the shift of the critical failure location.…”

“…Polymer composite structures exhibit much more significant fluid-structure interaction (FSI) than do metallic structures since the material densities of such composites are very comparable to that of water [2][3][4][5][6].…”