The Structure And Property Of Wooden Flooring In Gymnasium

Wooden flooring in gymnasium(WFG),which has particular reqirements on sports-function and protective-function as well as technical-function, is an engineered flooring composite conforming to biomechanics. It is an important component parts of gymnasium facility. However, research on WFG started late and related basic work was less accumulated in the world. The systematic study on structure, material, manufacturing technology, products property of WFG, on the correlation between sports biochemistry index and wooden flrooring structure were rarely reported. Therfore, with rapidly developing situation of Chinese sports and gymnasium buildings, structure and property research on WFG is great worth of theoretical and practical significance in China.Three kinds of structure form are adopted in this thesis.There respectively are double-layer structure made of surface layer floor,carcass flooring layer and double keel layer etc. material (structureⅠ), monolayer structure made of surface layer floor,carcass flooring layer and keel layer etc. material (structureⅡ) and no-keel structure made of surface layer floor and carcass flooring (structureⅢ).On the basic of systemic analysis on developing status and trend in domestic and abroad, WFG was sorted by purpose, structure and material in the study. Through analyzing WFG structure comparing with mainly relative products in the world, three typical strutures and a new material were selected as the investigated objects in the study. Aming at particular three functions and six property indexes of WFG, structures and performances were studied. The correlation between prevention of slipperiness and surface roughness was conducted; meanwhile correlation between coating types and thickness was also investigated. Based on orthogonal experiment, regression analysis and analysis of variance methods, the structural performance of three patterns of modular construction including double layers WFG for high-class events( PatternⅠ) were studied, and entired flooring construction of WFG was investigated and verified according to the standard of Wooden Flooring in Gymnasium(GB/T20239-2006). Dimension stability of entire construction of WFG was also studied. The correlation between structure of WFG and sports biochemistry index was investigated in accordance with the testing method designed by users.The main research achievements:(1) The important index for evaluating WFG surface property was sliding coefficient(Sp).Through comparing with three factors including grit number, types of coating and coating thickness, it can be found that grid number had maximal effect on the surface property, and types of coating taken the secend place. The negative correlation existed between grid number and surface roughness( R_a,R_z), as well as positive correlation between R_a,R_z and Sp.(2) The Sp of WFG, whether applied by Japan unite coating, grit-120 abrasive belt and 240μmcoating thickness or UV_painting, grit-240 abrasive belt and 140μmcoating thickness, can meet reqiurement of Wooden Flooring in Gymnasium(GB/T20239-2006).(3) The structural patterns of WFG had great influence on entired flooring construction. The force reduction( F_r ), vertical deformation( V_d)and ball rebound( B_r)indexes were adopted to evaluate performance of three patterns of WFG modular construction. The sequence of performance from good, better to best level was PatternⅢ, PatternⅡ, PatternⅠ, respectively.(4) For the double-layer load distribution strip of WFG ( PatternⅠ), regression equation were set up between cross section area and span of load distribution strip as well as property indexes of F_r,V_d,B_r.The interaction between span of load distribution strip and F_r , thickness and span of load distribution strip can be found significantly influence at 0.01 level by regression analysis. The span of load distribution strip was a major influencing factor to B_r.(5) F_r value was maximum under 500mm×500mm of X-Y span of load distribution strip and 50 mm×30 mm of cross section area. V_dvalue was maximum under 500mm×500mm of X-Y span of load distribution strip and 50mm×50mm or 70mm×30mm of cross section area. B_r value was maximum under 300mm×300mm of X-Y span of load distribution strip and 50mm×30mm of cross section area. The comprehensive analysis on performance index of F_r , V_dand B_r showed that optimized designing parameters were 500mm×500mm of X-Y span of load distribution strip and 50mm×3mm of cross section area.(6) Under the same material and structure of WFG, performance of entire construction was better than modular construction, and integrated performance of double-layer had advantage over single layer and non load distribution strip structure. WFG which was composed of load distribution panel with plywood and double-layer load distribution strip with LVL was investigated and verified according to standard of GB/T20239-2006 and DIN18032.2-2001. The result showed that F_r , V_d and B_r value was 55.5%, 2.36mm and 93.9%,respectively. The structural performance exceeded requirement of Chinese national standard for WFG. F_r , V_d and B_r value of WFG which was composed of single layer structure was 51.8%, 1.57mm and 95.4%, respectively.(7) The dimension stability of three typical patterns of WFG was tested for 8 weeks under three grades of temperature and humidity condition. The result showed that dimension changing and warping rate of WFG was minimum under 20℃and 75%RH condition , and structural stability was excellent.(8) A comparison between dimension changing and warping rate of three typical patterns of WFG, PatternⅠwas minimum, PatternⅢwas maximun and PatternⅡwas between them. PatternⅠhad excellent dimension stability. Three typical patterns were continually tested under selected temperature and humidity condition, warping changing rules showed stabilizing phenomena of PatternⅠ, PatternⅡand PatternⅢhappened after fourth week, sixth week and seventh week, respectively.(9) WFG sports biochemistry index was generally represented by blood lactate(BLA)and electromyogram (EMG). The structure of WFG had a significant effect on sports biochemistry index changing for sportsmen, BLA value increased with sport time prolonging and intensity increasing. The BLA value of PatternⅠwas less than PatternⅡand PatternⅢ, and also had lower rate of increase in three of them.(10) Different structure of WFG resulted in obvious difference on electromyogram (EMG) of biochemistry index for sportsmen, which including shrinking time, integral electromyogram (IEMG), mid-frequency(MF) and average power-frequency(MPF) of lateral head of gastrocnemius. Shrinking time of lateral head of gastrocnemius for PatternⅠwas shortest showing sportsmen need shorter time to do same jump action. IEMG of lateral head of gastrocnemius of PatternⅠw as always lower than that of PatternⅡand PatternⅢ,and mid-frequency(MF) and average power-frequency(MPF) of PatternⅠwas also lower than that of PatternⅡand PatternⅢ,namely indicated that sports burden on PatternⅠWFG was more gentle than PatternⅡand PatternⅢunder same sports burden.The innovating points in the paper:(1) WFG, which included assembled pattern, surface property, structure performance and dimension stability, were investigated for the first time in China. Performance index and testing methods were also put forward in the paper.(2) The advanced instrument and equipment were used for studying WFG on S_p,F_r,V_dand B_rindex, and mathematics model of correlation between WFG structure and performance was set up in the paper.(3) The BLA and EMG biochemistry index was firstly inducted into WFG research field in the world. The method was developed for revealing correlation between sports biochemistry index and structure of WFG, and correlativity between both was represented.(4) The structural design of WFG was firstly used by LVL material which improved phsical and mechanical performance. It provided scitific data supporting for new materials applied in making WFG, and also extended material sources for WFG purpose.