Research On Physical And Mechanical Properties And Design And Manufacture Of Structural Competition Model Materials

Structural modeling competition is an important discipline competition for college students in civil engineering and related majors,creative and challenging.It helps to consolidate and improve students’ professional knowledge,cultivate students’ innovative thinking,application ability and practical ability,and enhance team consciousness and cooperation ability.It is one of the National College Students’ science and technology innovation competitions approved by the Ministry of education.At present,universities,provinces and regions are actively holding the structural model competition.The materials such as white cardboard,bamboo skin,bamboo strip,white latex and 502 glue are widely used in structural model competition because of their good physical and mechanical properties and environmental protection and renewable.However,the material performance index given by the organizers is the approximate reference value.For the better development of the structure model competition,this paper makes a systematic research on the physical and mechanical properties and model design of materials commonly used in model competition.The following conclusions can be drawn through theoretical analysis and experiment:(1)The moisture content of white cardboard is very great,and the tensile strength is significantly reduced with the increase of humidity;Bamboo skin is less affected by humidity,and its tensile strength along the grain slightly decreases with the increase of humidity;(2)The tensile strength of white cardboard with different thickness is different,but the strength of the same white cardboard almost doesn’t change with the change of the width and number of layers;The tensile strength of bamboo skin with different thickness is different,the tensile strength of the same thickness bamboo skin increases slightly with the increase of width,and the tensile strength of the same width double layer bamboo skin is higher than that of the single bamboo skin;The tensile strength of monolayer bamboo skin is significantly increased after dipping 502 glue;(3)When the bamboo skin is made into a square hollow bar,the compressive strength of the bar with the same section length will hardly change with height in a certain height range;The compressive strength of rods made of bamboo strips decreases with the increase of height;(4)The elastic modulus of white cardboard with different thickness,bamboo skin with different thickness and bamboo strips of different specifications is different.When calculating and analyzing with software,it should be defined separately;(5)The quantity of different thickness of white cardboard is different,the density of bamboo skin and bamboo strips of different specifications are different,and the quantity of white cardboard and the density of bamboo wood increase with the increase of humidity.