Properties Of The Composite Material Of Sandwich Construction With Wooden Faceplate And A Paper Honeycomb Core

The sandwich construction which was consisted of wooden faceplate with a paper honeycomb retained the original advantages of the honeycomb material and greatly increased the mechanical intensity. Based on a number of domestic and foreign researches on metallic honeycomb and sandwich construction this paper analyses the properties of the packaging material of sandwich construction with wooden faceplate and a paper honeycomb core. Some points have been listed as follow.The coplanar distortion, mechanical properties and destroy modes of lateral depress were studied. The results show that the modes of coplanar distortion can be divided into three types. All types are related to the faceplate. Comparing to the honeycomb paperboard, the mechanical properties of sandwich structure are better. The formula of comparative coplanar MOE was deduced. The destroy modes of lateral depression can be divided into five types, which are wholly buckling, shearing crinkle, interfacial degumming, break of faceplate, and buckling of partial surface. The detailed statements of every mode are explained from the theoretical mechanics.The different face distortion, mechanical properties and destroy mode of flat crush were studied. The results show that the modes of different face distortion of different sandwich construction are similar. The mode can be divided into four stages, which are elastic stage, flectional stage, collapse stage and close-grained stage. The distortion mechanism of every stage is different. The sandwich structure will retain the advantage of the cushioning of honeycomb material. The energy was absorbed in the collapse stage. In relation to the paper sandwich construction, the flectional angle was put forward in the course of flat crush.The bending properties of different sandwich construction were studied. The results show, when the plywood was used for the faceplate, the sandwich construction was better than others. Based on the principle of simply supported beam and extended beam, the bending stiffness was analyzed. The similar formula was given about the wooden sandwich construction. There are four destroy modes of simply supported beam, which are shearing flection of a paper honeycomb core, shearing break of paper honeycomb core, flection of faceplate and yield behavior of faceplate. The detailed statements of every mode are explained from the theoretical mechanics.Based on the creep curve of sandwich construction, Burgers model can be used for the creep of the sandwich construction in the short run and analyzed on the rheological parameters. The creep speed of different sandwich construction was analyzed. Based on the grey analysis, the relation between instantaneous elastic and delayed elastic deformation is very close.Under the mutual action of fatigue and creep, beam compliance of sandwich construction can be as the damage parameter. The parameter can be divided into three stages under the mutual action. The relationships of the load holding time with the point of breaking life and the point of creep life were studied. The parameter B is reflected to the degree of mutual action of fatigue and creep.