基于虚拟梯度材料的螺栓结合面建模方法

Modeling method of bolted joint interface based on gradient virtual materials

为准确分析螺栓连接件的动态性能,提出了一种基于虚拟梯度材料的螺栓结合面建模方法。将螺栓连接结合部等效为一种局部的虚拟梯度材料,虚拟梯度材料与被连接件皆为固定连接。通过有限元方法获得了螺栓连接结合面的接触压强分布情况,在此基础上,应用胡克定律,推导了虚拟梯度材料的弹性常量与径向位置之间的关系。采用分层法建立了基于虚拟梯度材料的螺栓结合面有限元分析模型,分别获取了固结、传统虚拟材料与虚拟梯度材料结合面表征下试件的理论模态,并开展模态实验,从振型和固有频率两方面进行了对比分析,验证了本文虚拟梯度材料建模方法的有效性。结果表明:虚拟梯度材料模型的模态与实验模态的前6阶振型一致,前6阶固有频率的相对误差数值都在10%以内,建模精度高。

To improve the modeling precision of bolted joints,a new modeling method based on gradient virtual materials was proposed.First,the contact pressure distribution on bolted joint interface was obtained through interpolating and revising the contact interface force.Then,the analytical expressions of the elastic modulus and shear modulus were derived for gradient virtual material according to Hooke Law.By using a layering method,the analytical formulas of the gradient virtual material was inserted into finite element software to construct the interface model.Qualitative comparison of similar mode and quantitative comparison of corresponding natural frequency were carried out between the simulation and experimental results.It is shown that the first six order vibration shapes of the gradient virtual material models are consistent with experimental results.The modeling precision of the gradient virtual material model is much better than that of traditional virtual material model.