共查询到19条相似文献,搜索用时 171 毫秒
1.
橡胶纯剪试件变形与断裂的有限元分析 总被引:2,自引:1,他引:2
用非线性有限元法分析橡胶纯剪试件变形与理想纯剪变形之间的差异.结果表明试件中心接近纯剪,但是靠近自由边界的区域应力比较复杂,受自由边界影响的区域随应变的增加而减小,试件的宽高比越大变形越接近理想纯剪变形.对橡胶纯剪试件存在中心裂纹和边缘裂纹时的撕裂能进行计算,断裂形成大裂纹时撕裂能与裂纹尺寸无关,有限元解与以前的结果吻合较好;对于小裂纹,撕裂能与裂纹尺寸成线性关系.同时分析不同材料模型对橡胶纯剪试件变形和断裂的影响.分析表明,不同应变能函数的材料模型模拟的结果略有不同. 相似文献
2.
《中国工程机械学报》2017,(6)
对非线性弹性断裂能量释放率和裂纹扩展速度的关系进行研究,建立了橡胶材料的疲劳裂纹扩展寿命预测模型.对带有预制切口的橡胶试件进行疲劳试验,试验疲劳寿命与理论预测疲劳寿命误差值为8.72%,验证此法预测螺杆泵定子橡胶的裂纹扩展寿命是可行的.对螺杆泵进行有限元计算和力学分析,确定螺杆泵最大等效应力和最小等效应力,进而计算螺杆泵各段模型危险疲劳位置的应变能释放率范围,预测螺杆泵定子橡胶的疲劳扩展寿命,并与螺杆泵实际寿命基本吻合,为螺杆泵疲劳寿命的预测研究提供了具有一定实用性的理论及方法. 相似文献
3.
变幅载荷下隔振器橡胶材料裂纹扩展试验及建模方法 总被引:3,自引:0,他引:3
利用带单边缺口的纯剪试件,进行变幅疲劳载荷下隔振器橡胶材料的裂纹扩展试验。由于实测裂纹扩展长度存在波动,无法采用传统的割线法或七点多项式法来处理实测数据。为了解决传统方法的不足,利用幂函数来表征实测的裂纹扩展长度与循环次数的关系,进而确定隔振器橡胶材料的裂纹扩展速率及其裂纹扩展模型。基于建立的裂纹扩展模型,推导适用于哑铃试片的疲劳寿命预测模型。试制该型橡胶哑铃试片,并测试其疲劳寿命。通过对比哑铃试片实测寿命与预测寿命,验证变幅载荷下隔振器橡胶材料裂纹扩展模型的有效性。 相似文献
4.
橡胶弹性减振元件疲劳裂纹扩展寿命分析 总被引:11,自引:1,他引:10
对NR68橡胶纯剪切试样进行疲劳裂纹扩展试验,结果表明裂纹扩展率与撕裂能之间存在幂率关系.基于疲劳累计损伤理论,以撕裂能范围为损伤参量,建立橡胶疲劳寿命预测模型.对NR68橡胶裂纹扩展试验数据进行回归分析,拟合得出模型参数.综合应用有限元结构分析方法、橡胶材料等效应力计算方法和橡胶单侧切口拉伸(Single edge notched tensile,SENT)试样拉伸试验的应力应变数据,提出橡胶弹性减振元件撕裂能范围的计算方法,从而将弹性减振元件在复杂应力状态下的疲劳寿命问题转化为单向应力状态下橡胶材料的疲劳寿命问题.利用所建模型对锥形橡胶弹簧的疲劳寿命进行分析预测,并通过锥形橡胶弹簧台架疲劳试验进行验证,结果显示预测疲劳寿命是试验疲劳寿命的1.33倍,预测精度比较理想. 相似文献
5.
通过非线性有限元方法对橡胶材料分别采用Neo-Hookean及Mooney两种本构模型的橡胶层含角裂纹的剪切型橡胶减振垫进行数值分析.分别给出减振垫切向刚度与撕裂能随不同裂纹尺寸的变化关系,并对两种模型的切向刚度以及撕裂能进行比较.对受剪切载荷作用的减振垫在含不同深度橡胶层斜角裂纹的情况进行了分析.给出含斜角裂纹减振垫的切向刚度和撕裂能随着相对裂纹深度的变化情况.分析了不同载荷以及不同裂纹尺寸的减振垫的撕裂能变化. 相似文献
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通过Abaqus建立中碳钢构件的有限元模型,在给定初始裂纹的基础上,利用扩展有限元法(XFEM),仿真得到裂纹扩展过程中塑性应变能和弹性能的变化曲线。结合中碳钢试件的声发射试验,处理试验数据得到裂纹扩展过程中声发射信号的绝对能量曲线,以及通过红外热像仪的记录得到裂纹扩展过程中温度变化曲线。仿真得到的弹性能与试验中得到的能量曲线具有相同数量级,同时根据仿真得到的塑性应变能反向推导中碳钢最终断裂时温度变化显著的区域尺寸,与红外热像仪记录的温度变化显著的区域尺寸相符。试验得到的结果与仿真得到的结果基本吻合,这就为中碳钢疲劳寿命预测的声发射试验提供了理论依据。 相似文献
11.
Andrs Szekrnyes 《International Journal of Mechanical Sciences》2009,51(9-10):682-693
A closed-form solution for the compliance and the energy release rate of the updated version of the mode-III split-cantilever beam specimen is developed incorporating linear beam theories. Apart from bending and shear of the specimen, the Saint-Venant and free torsion effects are considered. The analytical solution is verified by finite element calculations, leading to the conclusion that the compliance is very accurately determined, while the energy release rate differs only with 5% compared to the finite element calculations. Based on the finite element analysis the recommended crack length range is given in order to design a configuration that gives 98% mode-III contribution to the total energy release rate. At the final stage the analytical model is applied to reduce the data from experiments performed on delaminated glass/polyester composite beams. The results show that the closed-form solution is in a very good agreement compared to the results by experiments, although this requires very accurate measurements. 相似文献
12.
The strain energy release rate is calculated for buckled one-dimensional delamination (through-width delamination) in composite laminates subjected to in-plane compression. A crack closure method based on plate finite elements is used in this analysis. For some laminates containing a one-dimensional delamination in cylindrical bending, closed form solutions are available. The present finite element solutions show excellent agreement with the analytical solutions. The strain energy release rate for various types of laminates is also calculated using the present finite element method. The results show that the strain energy release rate strongly depends on the type of laminate. 相似文献
13.
In-Kweon Kim 《Journal of Mechanical Science and Technology》1998,12(4):672-679
A simple method, which calculates the mode components of the strain energy release rate of free-edge delaminations in the
laminates, is proposed. The interlaminar stresses are evaluated as an interface moment and interface shear forces that are
obtained from the equilibrium equations at the interface between the adjacent layers. Deformation of an edge-delaminated laminate
is calculated by using a generalized quasi-three dimensional classical lamination theory developed by the author. The analysis
provides closed-form expressions for the three components of the strain energy release rale. The analyses are performed on
[+30/−30/90]s laminates subjected to uniaxial extension, with free-edge delaminations located symmetrically and asymmetrically
with respect to the laminate midplane. Comparison of the results with a finite element solution using the virtual crack closure
technique shows good agreement. The simple nature of this method makes it suitable for primary design analysis for the delaminations
of composite laminates. 相似文献
14.
基于有限元的呼吸裂纹转子动力学特性 总被引:2,自引:2,他引:0
采用有限单元法建立了含裂纹Jeffcott转子的有限元模型,利用应变能释放率方法得到了裂纹单元的刚度矩阵,采用应力强度因子为零法模拟了裂纹的呼吸效应.计算分析了在一个稳态旋转周期内裂纹开闭的规律,以及直斜裂纹转子振动响应的特点.计算结果表明,斜裂纹开始张开以及闭合的时间迟后于直裂纹,斜裂纹处于全闭与全开状态所经历的时间比直裂纹长.直斜裂纹转轴的1X和2X倍频响应随着裂纹深度的增加而增加,但3X倍频分量变化不大. 相似文献
15.
Time-independent orthotropic enrichment functions are introduced for dynamic propagation analysis of moving cracks in composites by the extended finite element method (XFEM). The proposed enrichment functions are derived from the analytical solutions for a moving/propagating crack in orthotropic media, and can be considered as a new extension to the available XFEM techniques for dynamic analysis of stationary and moving cracks in orthotropic materials. They are included within the framework of partition of unity and XFEM to enhance the accuracy of basic FEM solution near a moving crack tip in orthotropic media. The method allows for analysis of the whole crack propagation pattern on an unaltered finite element mesh, which is independently defined from the existence of any predefined crack or its propagation path. A combination of dynamic crack initiation toughness and crack orientation along the maximum circumferential stress is used to design a relatively simple and efficient formulation. Dynamic stress intensity factors (DSIFs) are evaluated by means of the domain separation integral method and the dynamic energy release rate. The time dependent XFEM equations are constructed by discretizing the standard weak formulation of the governing elastodynamics equation. They are solved by the unconditionally stable Newmark time integration scheme. A number of benchmark and test problems are simulated and the results are compared with the available reference results to illustrate the accuracy and efficiency of the proposed scheme. 相似文献
16.
通过非线性有限元方法对橡胶-钢球支座在扭转载荷作用下存在的椭圆表面裂纹情况进行了数值模拟,给出撕裂能与裂纹尺寸、载荷和橡胶层厚度的关系曲线.结果表明,对界面椭圆表面裂纹,同一裂纹深度,撕裂能随载荷的增加而增加,随橡胶层厚度的增加而减小.对橡胶层中间含椭圆表面裂纹,撕裂能随裂纹深度的增加而增加.最后,利用非线性回归工具得到撕裂能的经验计算式. 相似文献
17.
The impact-induced buckling and delamination of a thin coating was analysed for the purpose of predicting the amount of coating removed when a single particle was launched, at a given velocity, against a coated substrate. A novel post-buckling analysis is presented in which the coating is modelled as a clamped disk prevented from buckling at an arbitrarily set inner radius, due to the presence of the indenting particle. A method for calculating the arrest strain energy release rate and mode mix of interfacial delamination cracks, based on the coupling of the presented buckling analysis with an existing strain energy release rate analysis is then presented. A method to estimate the critical interfacial shear stress at crack initiation is also outlined. An accompanying paper compares experimental results with the results of this analysis, and shows how the results can be used in the context of blast cleaning. 相似文献
18.
Jae-Ung Cho Anthony Kinloch Bamber Blackman Sebastian Rodriguez Chong-Du Cho Sang-Kyo Lee 《International Journal of Precision Engineering and Manufacturing》2010,11(1):89-95
In this paper, a polymeric unidirectional carbon-fibre epoxy-resin composite is both experimentally and numerically investigated
to study the nonlinear material behavior of impacted DCB (Double Cantilever Beam) specimens. For the impact analysis, the
load and the displacement applied from pin onto end block as well as the crack energy release rate are measured and compared
with the finite element analysis results. The energy release rate is a critical measure of the resistance to crack propagation,
which can be estimated by the force and displacement at the crack tip. It is found that the energy release rate measured from
impact tests on the specimens is well predicted by the suggested finite element model in this study. 相似文献
19.
J. U. Cho S. K. Lee C. Cho F. S. Rodriguez Sanchez B. R. K. Blackman A. J. Kinloch 《Journal of Mechanical Science and Technology》2007,21(10):1671-1676
In this paper, a unidirectional carbon-fiber composite is both experimentally and numerically investigated to study the nonlinear
material behavior of impacted double cantilever beam (DCB) specimens. For the impact analysis, the load and the displacement
applied from pin onto end block as well as the crack energy release rate are measured and compared with the finite element
analysis results. The energy release rate is a critical measure of the resistance to crack propagation, which can be estimated
by the force and displacement at the crack tip. It is found that the energy release rate measured from impact tests on the
specimens is well predicted by the finite element model suggested in this study. 相似文献