CFRP吊系杆钢箱拱桥试验模型的设计

Test Model Design of Steel Arch Bridge with CFRP Suspenders and Tie Bars

以舞水大桥为实体桥,利用相似原理、方程分析法和量纲分析法,对该系杆拱桥进行相似分析,建立CFRP吊系杆钢箱拱桥试验模型。根据试验目的,模型选用弹性模型。因模型各物理量之间的方程关系式无法确立,故采用量纲分析法,根据第二相似定理,求得十六个π数,建立起各物理量的关系。再利用方程分析法,求弹性模量和密度需满足的条件。最后将所有物理量的相似常数都化为几何相似常数和弹性模量相似常数的函数。由于该实体桥是由钢绞线、平行钢丝和混凝土等材料组成,而模型选材时吊系杆采用碳纤维,拱肋和主梁采用全钢结构,同一结构中各处弹性模量比各不相同,通过把EA、EI、EW作为复合物理量解决了这一问题。建立相对应试验模型,并进行试验研究。

Taking the Wushui Bridge for example, the test model of steel arch bridge with CFRP suspenders and tie bars was established after analyzing this arch bridge with similarity principle, equation analysis and dimensional analysis method. Elastic model is selected according to the test purpose. Because the equation of each physical variable in the model could not be determined, the dimensional analysis method was adopted to obtain sixteen π numbers and establish the relationship among physical variables based on the second sire ilarity principle. Then the equation analysis method was used to figure out the conditions that the elastic modulus and density needed to satisfy, and finally the similarity constants of all physical variables were transformed to functions of geometric similarity constants and elastic modulus similarity constants. The bridge is composed of steel strand, parallel wire and concrete, whereas in the model material selection, the suspenders and tie bars were made from carbon fiber while the arch ribs and main beam were adopted all - steel structure, therefore the elastic modulus ratio of each part in the same structure was different. Through taking EA, El and EW as composite physical variables, the problem could be solved and the corresponding test model was built for further study.