多股簧动态参数检测技术及装备的研究

发布时间：2018-02-02 01:27

本文关键词： 多股簧冲击动态参数检测 PLC 疲劳试验　出处：《重庆大学》2011年硕士论文　论文类型：学位论文

【摘要】：多股螺旋弹簧(简称多股簧)是由多根钢丝绕成钢索后卷制而成的圆柱螺旋弹簧,与单股簧相比,这种弹簧具有较大的非线性阻尼,吸收冲击能力强,有更好的强度及独特的吸振、减振效果更好,强度更高、疲劳寿命更长。因此,在汽车仪器仪表减振系统、武器发射系统、航空发动机以及民用等多个领域中都具有重要的应用价值。多股簧在低速加载情况下,簧圈上任意质点的运动速度,沿弹簧轴向呈线性分布,受力端位移、速度最大,固定端位移、速度为零。因此,可以近似推算出簧圈上各质点位移、速度和加速度随时间的变化情况。但多股簧受到高速冲击载荷时,由于有质量、惯性,再加上自身的谐振,钢丝材料的弹性变形以及钢丝与钢丝之间的相对滑移而产生的摩擦阻力等诸多因素,簧圈的运动将变得非常复杂。具体地说,簧圈上各质点的位移和速度沿轴向不再是线性分布,而是以纵波的形式向固定端传递,并在固定端反射。因此,现有的弹簧拉压试验设备和检测技术肯定不能适用。另外,现在对冲击载荷下多股簧疲劳寿命的检测,只能进行实弹射击测试,这样成本高、周期长、效率低。故目前只能简单地用低速谐波疲劳试验代替高速冲击疲劳试验,进而求取多股簧冲击疲劳寿命近似结果。针对当前弹簧检测设备存在的问题,本文提出了全新的螺旋弹簧动态参数检测的数学模型并基于多股簧开发了相应的试验设备,以用于检测冲击载荷下多股簧的动态参数和模拟多股簧的实际冲击工况。本课题研究的主要内容: ①提出了冲击载荷下螺旋弹簧动态参数的数学模型,用于检测螺旋弹簧冲击载荷下任意簧圈上任意质点位移、速度和加速度随时间的变化规律,为多股簧的动态设计理论提供试验依据。 ②开发了一套冲击载荷下多股簧动态参数的检测设备,具体涉及到该检测设备的机械结构设计,数据采集模块和数据分析模块。 ③在上述检测设备基础上,用PLC控制器实现了原有设备单次冲击到连续冲击的转变,用于模拟多股簧的实际冲击工况。 ④应用上述自主开发的检测设备基于多股簧进行了试验测试,研究了多股簧在冲击载荷下内部簧圈的变形机制和冲击疲劳试验对其刚度的影响。
[Abstract]:Multi-strand helical spring is a kind of cylindrical helical spring, which is made up of many steel wires. Compared with single-strand spring, this kind of spring has more nonlinear damping and stronger shock absorption ability. Have better strength and unique vibration absorption, better vibration absorption effect, higher intensity, longer fatigue life. Therefore, in the automotive instrument damping system, weapon launch system. The aero-engine as well as the civil and so on many fields all have the important application value. Under the condition of low speed loading, the velocity of any mass on the spring coil is linear along the spring axial direction, the displacement of the bearing end is the largest, the displacement of the fixed end is zero, and the velocity is zero. The variation of mass displacement, velocity and acceleration with time on the spring coil can be estimated approximately. However, when the multi-strand spring is subjected to high speed impact load, the mass, inertia and its own resonance can be obtained. The elastic deformation of steel wire material and friction resistance caused by relative slip between steel wire and steel wire will make the movement of spring coil very complicated. The displacement and velocity of the particles on the spring ring are no longer linear distribution along the axial direction, but are transmitted to the fixed end in the form of a longitudinal wave and reflected at the fixed end. The existing spring tension and compression test equipment and testing technology certainly can not be applied. In addition, the fatigue life of multi-strand spring under impact load can only be tested with live fire, which is high cost and long period. Therefore, the low speed harmonic fatigue test can only be used to replace the high speed impact fatigue test, and the approximate results of the impact fatigue life of the multi-strand spring can be obtained. Aiming at the problems existing in the current spring detection equipment, this paper presents a new mathematical model for the dynamic parameter detection of the helical spring and develops the corresponding test equipment based on the multi-strand spring. It is used to detect the dynamic parameters of multi-strand spring under impact load and to simulate the actual impact condition of multi-strand spring. The main contents of this research are as follows: The main contents are as follows: 1. A mathematical model of the dynamic parameters of helical spring under impact load is presented, which is used to detect the variation of displacement, velocity and acceleration of any mass point on any spring ring with time under the impact load of helical spring. It provides experimental basis for dynamic design theory of multi-strand spring. (2) A set of measuring equipment for dynamic parameters of multi-strands spring under impact load is developed, including mechanical structure design, data acquisition module and data analysis module. 3 on the basis of the above testing equipment, the PLC controller is used to realize the transformation from single impact to continuous impact of the original equipment, which is used to simulate the actual impact condition of multi-strand spring. (4) based on the multi-strand spring, the deformation mechanism of the inner spring and the effect of the impact fatigue test on the stiffness of the spring were studied by using the self-developed testing equipment mentioned above.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH135

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