论文部分内容阅读
为解决圆弧拱在大矢跨比情况下等效替代抛物线拱精度差的问题,将双曲余弦函数曲线引入到抛物线拱侧倾稳定的解析计算中,在证明双曲余弦函数曲线比圆弧线拟合度更优的基础上,基于最小势能原理,以双曲余弦函数曲线等效替代抛物线,同时考虑副拱作用,推导出了保向力作用下带副拱的抛物线平行双肋拱系侧倾临界荷载的解析计算公式。随后,利用有限元数值算例验证了所得公式的正确性;最后通过公式计算讨论了各参数对带副拱的抛物线双肋拱系侧倾失稳临界荷载的影响。研究结果表明:计算公式与有限元分析结果的差值最大不超过3.62%,所得公式具有非常高的工程精度;以圆弧拱近似替代抛物线拱在矢跨比较大的情况下结构的侧倾临界荷载计算结果会产生较大误差,最大有10.47%,用双曲余弦函数曲线等效替代抛物线更优;相对于横撑在拱切向平面内的抗弯刚度、横撑数量、双肋间距离和矢跨比来说,副拱在拱切向平面内的抗弯刚度和主、副拱相交位置不是影响保向力作用下带副拱的抛物线平行双肋拱系侧倾稳定的关键因素。推导所得解析计算公式简便且精度高,对工程初步设计具有一定的实用值价,且为参数的合理设置提供了参考。
In order to solve the problem that the accuracy of the circular arc arch is equivalent to that of the parabolic arch equivalent to that of the large pitch-span, the hyperbolic cosine function curve is introduced into the parabolic arch stability analysis. When the hyperbolic cosine function curve is proved to be more accurate than the arc line Based on the principle of minimum potential energy, the parabola with parallels with double arches under the action of the retaining force is deduced by replacing the parabola with the hyperbolic cosine function curve and taking the side-arch effect into account. Analytical formula of critical load. Subsequently, the correctness of the formula was verified by numerical examples. Finally, the influence of various parameters on the critical load of roll instability of parabola double-rib arch with secondary arches was discussed through formula calculation. The results show that the difference between the calculation formula and the result of finite element analysis does not exceed 3.62%, and the obtained formula has very high engineering precision. With the circular arch approximating the parabolic arch instead of the parabolic arch, The results of load calculation will produce large errors, with a maximum of 10.47%. It is more effective to replace the parabola with hyperbolic cosine function curve. Compared with the flexural rigidity, the number of bracing, the intercostal distance For sag ratio, the flexural rigidity of the secondary arch in the tangential direction of the arch and the intersection of the primary and secondary arcs are not the key factors affecting the roll stability of parabolic parallels double rib arch system with secondary arch under the effect of retaining force. The derivation of the analytic formula is simple and accurate, has some practical value for the preliminary design of the project, and provides a reference for the reasonable setting of parameters.