Investigation Of Mechanical Properties Or3D Two-Layer Hollow Integrated Sandwich Composites

3D two-layer hollow integrated sandwich composites with good integrated capabilityimproved crash worthiness of composite as hollow Integrated Sandwich Composites. Highlyunstable problem of hollow integrated sandwich composites with high degree core is solved byreplacing by Hollow two-layer integrated sandwich composites. It is necessary to do sometheoretical and experimental research for the composite. Mainly includes the following content:1) The first part of the theoretical analysis method of material mechanical properties werestudied. Micro structure of composite is determined based on the assumption theory byunderstanding the structure parameters of fabric. The symmetry repeated unit cell is selected.The theoretical mechanical model is established to predict the mechanical properties ofcomposite by the method of average volume. The variation tendency is cased by elastic modulusof yarn and panel thickness parameters changing are also investigated.2) In the second part, the finite element model of the two-core sandwich composite isestablished, the flatwise tensile strength、the flatwise compressive strength、the edgewise tensilestrength and the edgewise compressive strength of composite are predicted by method ofnumerical simulation. The influence of parameter modification for the composite performanceare also studied.3) At last, Specimens of3D two-layer hollow integrated sandwich composites aremanufactured. Tensile and compressive tests for mechanical properties of composites areperformed. The accuracy of theoretical analysis method is verified by discussing the errorbetween experimental data and theoretical date.