《基于ANSYS的柴油分馏塔的固有频率的计算》-毕业论文.doc

摘 要 在化工生产中，分馏塔承受筒体内压、自重、风载荷和地震载荷的作用容易产生载荷振动和诱导振动。当振动频率接近于塔的自振频率时，塔就会发生共振、可能导致设备的破坏。因此，如何减小塔设备受风力作用而产生的诱导振动造成严重的危害，提高塔设备的抗振能力都是需要在设计时予以考虑的问题。 本论文的题目是“基于ANSYS的柴油分馏塔的固有频率的计算”。本文以柴油分馏塔为研究对象，应用ANSYS有限元软件对设备进行了固有频率的计算，首先采用SHELL63单元建立分馏塔的三维实体模型，然后用自由分网的方法对其进行网格划分，施加约束和载荷，最后应用模态分析功能求解出柴油分馏塔的固有频率和振型。然后利用集中质量法假设把均布质量作为一个与之相当的集中质量放置在塔的顶端，根据动能平衡的原理以及虚梁法可以确定不等截面悬臂梁式柴油分馏塔自振周期。这一结果表明基于ANSYS的有限元法对柴油分馏塔自振周期的计算准确性高，计算方便，为工程上其他复杂模型固有频率的计算提供了方法依据。 关键词：ANSYS；柴油分馏塔；固有频率；振型 Abstract In chemical production, fractionation tower were prone to vibration and induced vibration loads beacause of withstanding the body cylinder pressure, dead weight, wind loads and seismic loads. When the vibration frequency close to the tower natural frequency, the tower resonance occurs, which may result in equipment damage. Therefore, how to reduce the damage due to wind-induced vibration effect to improve the towers vibration capabilities are required to be considered in the design. The thesis is calculations of diesel distillation tower natural frequency on ANSYS , and mainly study for the diesel distillation column. First, I apply SHELL63 element in finite element software ANSYS to establish three-dimensional solid model of distillation tower, and then to mesh and impose constraints and loading, modal analysis, and finally solve the diesel distillation tower natural frequencies and mode shapes. Then assume the uniform quality as an equivalent concentrated mass placed in the towers top based on Lumped mass method, and determine the natural cycle of diesel fractionator according to the principle of kinetic energy balance as well as virtual cantilever beam method. The results show that iesel fuel distillation column calculation of the natural cycle based on the ANSYS finite element method is of high accuracy, easy to calculate, providind a method of calculating the natural frequency for the other complex models. Key words：ANSYS；Diesel fractionator tower；Natural frequency of vibration；Vibration model 目