基于几何非线性动力组合地基梁模型的漏粪地板自振特性

针对农业工程中猪舍漏粪地板的动力响应问题，采用静力分析方法，对漏粪地板进行自振特性进行研究。在考虑地基的压缩和剪切刚度、梁的弯曲和剪切变形、运动的平动和转动惯性力以及轴力的二阶效应的基础上，建立了几何非线性压剪平转动Timoshenko弹性地基梁动力基本方程，并给出了动力位移和内力方程；提出了组合地基梁的自振特性分析方法，对典型猪舍漏粪地板自振周期及振型进行了计算。结果表明：组合地基梁的周期及振型规律明显异于普通梁；不同结构参数对漏粪地板自振周期的影响程度各不相同：端部缝间板条不改变振动特性；支承长度和地基刚度作用显著；剪切变形、转动惯性力和地基剪切刚度引起的偏差较小，可忽略其影响。本研究建立的几何非线性动力组合地基梁模型能够用于猪舍漏粪地板舒适性验算和动力安全性设计。

Natural vibration characteristics of leakage floor based on geometric nonlinear foundation beam model

Aimed at the dynamic response problem of the leakage floor, the static analysis method is adopted to study the natural vibration characteristics of the leakage floor. The dynamic fundamental equations are established by considering compression and shear of foundation, translation and rotation inertia of beam with Timoshenko-Beam model and second-order effect of axial force. The dynamic displacement and internal force equations are derived. A method for analyzing the natural vibration characteristics of combined foundation beams is proposed, and the natural vibration period and mode shape of the floor are calculated. It results showed that: The period and mode shape of the combined foundation beam obviously differ from those of ordinary beams. Different structural parameters have different degrees of influence on the natural vibration period of the leakage floor, while the slats between the end joints do not change the vibration characteristics. The effects of bearing length and foundation stiffness are significant, the deviations caused by shear deformation, rotational inertia and foundation shear deformation are small and can be ignored. In conclusion, the geometric nonlinear dynamic combined foundation beam model is established, which can be used for comfort check and dynamic safety design of the piggery floor.