生物组织协同减振机理及仿生减振装置设计方法研究

发布时间：2018-06-08 00:32

本文选题：仿生减振 + 生物原型　；参考：《山东大学》2014年博士论文

【摘要】：机械装备中大量使用的质量-弹簧-阻尼减振装置,当承受多种复杂激励(如各种工况下工作载荷、不同环境激励、基础干扰等)耦合作用或激振频率发生偏移时,减振效果明显劣化。本文基于自然界生物机体可适应外部载荷的强度、频率的变化调整自身结构实现高效减振的事实,以啄木鸟头和马腿为仿生原型,对其生物组织的非线性特性、减振机理以及仿生减振装置设计、优化方法进行系统研究,为工程实际中进行减振装置的仿生设计与应用提供理论和技术支持。利用非线性动力学和生物力学理论,阐明了啄木鸟头部组织、马腿部组织各自的协同减振作用机理。啄木鸟头部组织的协同减振作用体现在：在啄击力作用下,头部喙的非线性弹性力、肌肉软组织的非线性弹性力和阻尼力、脑脊液的流体阻力能够有机协作,协同一致共同实现保护大脑避免冲击损伤这一自标；马腿部组织的协同减振作用体现在：在复杂路况机理作用下,腿部骨骼的弹性力、肌肉的非线性肌肉力、足底“肉垫”的阻尼力能够协同一致共同避免机体在路况带来的拉伸、压缩、弯曲、剪切等变形过程中受到损伤。考虑啄木鸟头部喙的刚度非线性、肌肉软组织的刚度和阻尼非线性、脑脊液流体阻力以及马腿部非线性肌肉力等因素的影响,分别建立了啄木鸟头、马腿协同减振系统非线性动力学模型,探讨了啄木鸟头部喙、肌肉软组织、脑脊液和马腿部骨骼、肌肉、足底“肉垫”的刚度和阻尼变化规律。根据增量谐波平衡理论,对啄木鸟头部减振系统动力学模型进行了基谐波附近振动的近似解析,计算获得了啄木鸟大脑的频响特性。建立了变刚度变阻尼减振系统实验台。完成了实验台本体、质量元件、非线性刚度元件、非线性阻尼元件、振动测试与采集分析系统的设计、选型与搭建工作,实现了系统刚度、阻尼的可控、可调,振动量的可实时测量。对提出的含立方刚度和平方阻尼作用的啄木鸟头部模型系统的动力学特性进行了实验研究,主要包括系统频响特性实验和减振性能实验等方面。结果表明：设计条件下被保护对象频响曲线的共振区狭窄,激励频率远离共振区后振动幅值迅速下降,保证了系统在宽频域内始终保持较好的减振效果,测试频率范围内系统的振动传递率可限制在10%以内,取得了良好的减振效果。试验获得的系统频响曲线与仿真结果对比分析说明对啄木鸟头部生物组织的协同减振作用及动力学模型理论和数值分析的结论是有效的。在对生物组织非线性特性及其协同减振作用理论和实验分析基础上,仿照啄木鸟头部喙的非线性刚度、肌肉软组织的非线性刚度和阻尼、脑脊液的流体阻力等作用设计了磁流变弹性体单元、可调阻尼孔空气弹簧减振单元、粘弹阻尼减振单元,仿照马腿肢体结构设计了仿肢体弹簧铰接减振单元,根据生物组织的协同减振作用机理,提出了仿生减振功能单元的模块组合设计方法。并推导了各个仿生减振单元的刚度和阻尼随结构参数和外部激励的变化关系,给出了各减振单元进行组合设计的原则,以空气弹簧仿生减振单元和粘弹阻尼仿生减振单元为例,研究了主要结构参数对单元非线性刚度和阻尼的影响规律。针对机械设备愈加复杂的动力学环境,以承载大、受多种耦合激励(负载激励、环境及基础干扰等)作用的典型机加工设备——JA31-160C型闭式单点压力机为例,研究运用“仿生减振功能单元模块组合设计法”法进行压力机基础减振装置设计的有效性。根据结构动力修改理论,以负载激励、环境激励等耦合激振下最小振动传递率和固有频率尽量远离共振频率为双目标函数,提出一种适合多目标、可考虑负载激励和环境激励耦合作用的仿生减振装置动态优化方法。对优化得到的压力机基础仿生减振装置和压力机目前常用的阻尼弹簧减振器和高性能弹性体阻尼模块进行了对比分析,结果表明：仿生减振装置可以有效避免目前压力机基础减振结构的设计先天不足,而且稳定性好,抗干扰能力强,减振性能较目前常用的减振装置得到明显改善。本课题得到教育部博士学科点专项科研基金(20110131110043)和山东省科技发展计划项目(2011GGX10328)的资助。
[Abstract]:A mass - spring - damping vibration damping device used in mechanical equipment is widely used in mechanical equipment . When subjected to various complex excitation ( such as working load under various working conditions , excitation of different environments , basic disturbance , etc . ) coupling or excitation frequency , the damping effect is obviously deteriorated . Based on the fact that the natural organism can adapt to the strength and frequency of external load , the nonlinear characteristics , vibration damping mechanism and bionic vibration damping device design and optimization method of the biological tissue are studied , and the theory and technical support are provided for the bionic design and application of the vibration damping device in engineering practice .

Based on the nonlinear dynamics and biomechanics theory , the mechanism of synergistic damping between the head tissue and the leg tissue of the woodpecker is illustrated . The synergistic damping effect of the head structure of the woodpecker is shown as follows : under the action of pecking force , the nonlinear elastic force of the head beak , the nonlinear elastic force and the damping force of the soft tissue of the muscle , the fluid resistance of the cerebrospinal fluid can organically cooperate , and the self - standard of protecting the brain to avoid shock damage can be realized in concert .
Based on the theory of incremental harmonic balance , the dynamics model of the head beak , muscle soft tissue , cerebrospinal fluid and horse ' s leg bones , muscle and foot sole of the woodpecker is analyzed , and the frequency response characteristic of the woodpecker ' s brain is calculated .

In this paper , the design , type selection and construction of the system of variable stiffness damping and damping are established , and the design , selection and construction of the system are carried out . The dynamic characteristics of the system stiffness and damping are studied experimentally . The results show that the vibration transfer rate of the system is limited to 10 % . The results show that the system frequency response curve and the simulation results show that the synergistic damping effect of the system and the theoretical analysis of the dynamics model are effective .

On the basis of the theoretical and experimental analysis of the nonlinear characteristics of the biological tissue and its synergistic damping effect , the nonlinear stiffness of the beak of the woodpecker , the nonlinear stiffness and damping of the soft tissue , the fluid resistance of the cerebrospinal fluid are designed .

On the basis of the theory of structural dynamic modification , the minimum vibration transfer rate and natural frequency as far away from the resonant frequency as the double objective function are studied by means of the combined design method of the " bionic vibration damping function unit module " . The results show that the bionic vibration damping device can effectively avoid the design of the foundation vibration damping device and the high performance elastic damping module of the press .

This subject is funded by the Special Scientific Research Fund ( GB 131110043 ) and the Science and Technology Development Plan Project ( 2011GGX10328 ) of Shandong Province .
【学位授予单位】：山东大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TB535.1

【参考文献】