| Wood Plastic Composites (WPC), a new kind of material friendly to environment, are being applied to many fields such as architecture, landscapes, furniture, interior fitment, casing, vehicles, shipbuilding and so on. Its practical application has a good prospect, but man know it too little to make good use of it. Now many researchers focus their attention on compositions or performances of WPC, but give little attention to connections of WPC frameworks. Studying on connections of WPC frameworks will not only promote the quality of WPC products but also expand the application areas of WPC. All those are beneficial to popularizing WPC. The paper studied the connections of WPC constructions, looking on constructions and screws as objects, by means of static test and dynamic test. The studying emphases include:(1) The effects of oriented aperture on the strength of WPC constructions(2)The effects of loading modes on the strength of WPC constructions(3) The effects jointing modes on the strength of WPC frameworks constructions(4)The effects of repeated dismounting times on the strength of WPC constructions(5)The effects of the interaction of low-cycle fatigue and creep on the strength of WPC constructionsThe results of tests showed:(1) The screw-holding difference from three sides of WPC was not significant, so we could consider WPC as isotropic material. The screw-holding of WPC was better and similar to hard wood. Connecting WPC frameworks with screws need to choose a suitable ratio of screw diameter to oriented aperture which varied from 83% to 88%.(2) To the WPC used in the tests for this paper, the jib lengths of L-type constructions should not exceed 230mm under the tension stress and not exceed 170mm under compression stress. The optimum jib length to the former was approximately 190mm and to the latter was 150mm. Equivalent elastic modulus, angular strain and resistance moment could be used in analyzing the strength of WPC constructions.(3) Compared with ferruginous tapping screw and wood screw, stainless steel tapping screw was the best one to be used in connecting WPC constructions. Whether in L-type constructions or T-type ones, the strength of coplanar screw connections has the approximately same value. But the rigidity of coplanar screw connections was better than that of no coplanar screw connections. The accuracy of constructions assembly has an important effect on the strength of constructions. In practice, the total strength of WPC frameworks could be promoted by promoting assembly accuracy.(4) With the increase of repeated dismounting times, both the bi-screws holding and static bending strength reduced. When it was less than 10, the effect of repeated dismounting times on both bi-screws holding and static bending strength was not significant. But when it was more than 10, the effect of repeated dismounting times on both bi-screws holding and static bending strength was on the contrary. So WPC constructions could be repeated dismounting, but its times should not be more than 10.(5) The curves of fatigue/creep had three stages at a 60% and 80% breaking load, namely, the transient elastic deformation stage, the curve of fatigue/creep had foregoing two stages at a 40% breaking load. The delayed elastic deformation stage appears later, and internal angle of rotation increases more quickly. The interaction of fatigue and creep was not a simple summation. When hold time was shorter, fatigue damage was leading, but with the increase of hold time, creep damage increased.(6) With the increase of hold time, the life of WPC construction increased in the beginning, and then decreased, this show that the integrated damage decreased in the beginning and then increased. Upper temperature might decrease the brittleness of WPC, and the connection had a bigger internal angle of rotation when failure.
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