共查询到20条相似文献,搜索用时 140 毫秒
1.
2.
SiC/环氧树脂复合材料冲蚀磨损性能的研究 总被引:1,自引:1,他引:0
采用环氧树脂为粘接剂制备了SiC/环氧树脂复合材料,在自制的射流式冲蚀磨损试验机上研究了SiC/环氧树脂的冲蚀磨损性能.结果表明:大尺寸SiC颗粒制备的复合材料较小尺寸SiC颗粒制备的复合材料具有更好的冲蚀磨损性能,且大尺寸SiC颗粒复合材料的冲蚀磨损性能优于Q235钢,而小尺寸SiC颗粒复合材料则低于Q235钢.随着冲蚀角度的变化,其平行材料表面的切削分量和垂直材料表面的冲击分量将会发生变化,低角度冲蚀磨损机理以显微切削和碾压造成环氧树脂及SiC颗粒的层片状脱落为主转变为高角度冲蚀磨损以SiC颗粒碎裂造成环氧树脂疲劳脱落为主. 相似文献
3.
利用MG-200型摩擦磨损试验机研究了炭纤维增强环氧树脂复合材料/N80钢的摩擦学性能,考察了介质温度对摩擦学性能的影响;用扫描电子显微镜分析了磨损表面形貌.结果表明:在干摩擦条件下,炭纤维增强环氧树脂复合材料与N80钢对摩时的摩擦系数较低,炭纤维增强环氧树脂复合材料的磨损主要表现为树脂基体脱落碳化和炭纤维的折断剥落,偶件钢环则呈现明显的磨粒磨损特征;在油井产出液润滑下炭纤维增强环氧树脂复合材料的磨损率较低,摩擦系数和磨损率随着润滑介质温度的升高而增大,偶件钢环则呈现明显的磨粒磨损和腐蚀磨损特征. 相似文献
4.
本文首先通过落锤低速冲击实验测试了纯玻璃纤维增强环氧树脂复合材料和304不锈钢丝网(SSWM)/玻璃纤维混杂复合材料的力学性能,探究了SSWM嵌入数量对混杂复合材料抗冲击性能的影响.随后采用Abaqus有限元软件建立了混杂复合材料的低速冲击模型,分别采用三维Hashin失效准则和Jason-Cook破坏准则模拟了纤维/基体和SSWM的损伤;建立了基于表面接触的内聚力模型来模拟界面分层;编写了VUMAT用户子程序定义混杂复合材料层合板的渐进失效过程.结果表明:相较于纯玻璃纤维增强环氧树脂层合板,SSWM/玻璃纤维混杂增强环氧树脂层合板的抗冲击性能更优,其中铺层形式为铺层III的混杂复合材料抗冲击性能最佳.通过对比发现有限元仿真结果与实验结果吻合良好,表明建立的模型适用于SSWM/玻璃纤维混杂增强环氧树脂复合材料低速冲击损伤的评估.通过分析仿真结果发现混杂复合材料的低速冲击损伤主要是冲击区域的纤维断裂、基体破坏和层间分层;SSWM通过吸收和传递冲击能量从而提升了混杂复合材料的抗冲击性能. 相似文献
5.
多壁碳纳米管/环氧树脂纳米复合材料的摩擦磨损性能研究 总被引:6,自引:0,他引:6
采用浇铸法,利用超声分散制备了多壁碳纳米管(MWNTs)/环氧树脂(EP)纳米复合材料,研究了MWNTs的添加量及分散程度对复合材料表面形貌和摩擦磨损性能的影响,并探讨了影响MWNTs/EP复合材料摩擦磨损性能的因素.结果表明:随着MWNTs加入量的提高(1%~4%),复合材料的摩擦系数和磨损率均呈现降低趋势,摩擦系数由0.60降到0.22,磨损率由1.11×10-4mg/(N·m)降为2.22×10-5mg/(N·m);在MWNTs添加量(1%)相同的情况下,MWNTs分散程度高的复合材料的摩擦性能更好.纯环氧树脂与45#钢对摩时发生粘着磨损和疲劳剥落,而由于MWNTs的增强和自润滑作用,MWNTs/EP复合材料的粘着磨损和疲劳剥落显著减轻. 相似文献
6.
7.
为研究碳纤维/环氧树脂复合材料在超高速撞击下的成坑特性,利用二级轻气炮开展了直径为1.00~3.05 mm的铝球以3.0~6.5 km/s的速度正撞击尺寸为100 mm×100 mm×20 mm的碳纤维/环氧树脂复合材料靶板的实验,获得了碳纤维/环氧复合材料靶板的成坑形貌特征,并测量了坑深、成坑表面积、表面损伤面积等尺寸。结合文献数据分析了靶板的无量纲成坑深度p/dp、无量纲坑径系数Dh/dp、表面损伤面积等效直径De等随撞击速度、撞击能量的变化规律。结果表明:碳纤维/环氧树脂复合材料的无量纲成坑深度p/dp和无量纲坑径系数Dh/dp均与撞击速度呈2/3次幂关系;表面损伤面积等效直径De与弹丸撞击能量E呈幂函数关系;成坑深度大于成坑半径。 相似文献
8.
研究了炭纤维织物/环氧(CF/EP)复合材料与45#钢在环-环端面干摩擦状态下的摩擦磨损特性,考查了制备工艺和MoS2与石墨不同配比等对CF/EP复合材料干摩擦性能的影响,采用扫描电子显微镜观察复合材料及其偶件磨损表面形貌.结果表明:半干法制备的环氧树脂体积分数为40%的CF/EP复合材料的摩擦系数稳定;纯CF/EP复合材料主要表现为粘着磨损特性;MoS2与石墨改性后复合材料摩擦磨损性能明显改善,质量比为1.5∶1的MoS2与石墨改性CF/EP复合材料具有最佳的摩擦磨损性能,其稳态摩擦系数为0.14~0.15,磨损量3.15×10-5 mg/r. 相似文献
9.
10.
11.
二乙基二硫代氨基甲酸镧配合物润滑脂添加剂的摩擦学研究 总被引:7,自引:2,他引:7
在空气环境下,制备了一种二基二硫代氨基甲酸与稀土元素镧的配合物(ELaDTC)。利用四球试验机评价了其在通用锂基润滑脂中的极压和抗磨损性能,并与常用二烷基二硫代磷酸锌(ZDDP)进行了对比。结果表明:此类稀土配合物能够显著提高锂基润滑脂的极压性能,且优于ZDDP;同时具有良好的抗磨损性能,在添加质量分数为1%时ELaDTC的抗磨损效果优于ZDDP。采用XPS对ELaDTC的极压抗磨机理进行了分析, 相似文献
12.
统一强度准则下厚壁圆筒的弹脆塑性承载能力分析 总被引:1,自引:0,他引:1
应用统一强度准则和弹脆塑性变形模型,研究材料具有软化效应的厚壁圆筒的承载力。分别导出在内压及外压作用下厚壁圆筒弹脆塑性承载力的计算公式。这些公式不仅给出了以往基于Mohr-Coulomb准则和广义双剪准则的结果,而且给出了一系列新的结果,因而本文的结果可适用于多种材料。实例表明材料软化效应以及分析中所选用的强度准则对厚壁圆筒承载力具有重要影响。因此,在确定厚壁圆筒承载力时,应该合理地选用材料的软化参数及强度准则。 相似文献
13.
本文利用线性软化模型及Mohr-Coulomb塑性条件,对岩土类材料的简支及固支圆板进行了承载特性分析。分析结果表明,由于岩土类材料的应变软化性质,结构呈现渐进破坏,且承载特性与材料的软化程度有关。 相似文献
14.
In the Beverton-Holt difference equation of population biology with intrinsic growth parameter above its critical value, any
initial non-zero population will approach an asymptotically stable fixed point, the carrying capacity of the environment.
When this carrying capacity is allowed to vary periodically it is known that there is a globally asymptotically stable periodic
solution and the average of the state variable along this solution is strictly less than the average of the carrying capacities,
i.e. the varying environment has a deleterious effect on the state average. In this work we consider the case of a randomly
varying environment and show that there is a unique invariant density to which all other density distributions on the state
variable converge. Further, for every initial non-zero state variable and almost all random sequences of carrying capacities,
the averages of the state variable along an orbit and the carrying capacities exist and the former is strictly less than the
latter.
2000 MSC: 37H10; 39A11; 92D25. 相似文献
15.
An improved ox-cart was developednt based on survey and testing of traditional and pneumatic-tyred carts. An improved cart is provided with a braking system, proper balance, a steel axle, increased carrying capacity, quicker access for lubrication, seating arrangements for passengers, and provision for carrying low-density material like husk, straw, etc. The performance evaluation studies revealed that the carrying capacity of this cart is 12 quintals (1200 kg) on loose field terrain, and that the draft required is 125 kg (1.2 kN). An improved ox-cart gave better results than a traditional cart in respect of draft and power requirements. 相似文献
16.
An endeavor has been made to discuss the behavior of hydromagnetic squeeze film between two conducting rough porous conical
plates. The plates are considered to be electrically conducting and the clearance space between them is filled by an electrically
conducting lubricant. A transverse magnetic field is applied between the plates. Efforts have been made to solve the concerned
Reynolds’ equation with the associated boundary conditions to get the pressure distribution. This in turn, is used to obtain
the expression for load carrying capacity leading to the calculation of the response time. The results are presented graphically
as well as in tabular form. It is suggested by the results that the bearing system records an enhanced performance as compared
to that of a bearing system working with a conventional lubricant. It is noticed that the pressure, load carrying capacity
and the response time increase steadily with increasing values of the magnetization parameter. In general, the bearing suffers
owing to transverse surface roughness. However, the negatively skewed roughness tends to better the performance of the bearing
system marginally. This performance gets further improved especially, when the negative variance is involved. It is observed
that the semi-vertical angle increases the load carrying capacity. Besides, the conductivity also increases the load carrying
capacity significantly. In addition, it is revealed that the negative effect induced by the porosity can be neutralized to
a nominal extent by the positive effect of the magnetization parameter in the case of negatively skewed roughness in the presence
of negative variance. Thus, this study provides ample scopes for improving the performance of the bearing system considerably
by choosing a suitable combination of magnetization parameter, semi-vertical angle and the conductivities of the plates. 相似文献
17.
18.
微尺度气体滑动轴承的Monte Carlo模拟与性能分析 总被引:2,自引:2,他引:0
改进了直接模拟Monte Carlo (DSMC)方法并模拟研究了轴承构型、滑动速度、壁温及环境压力对微气体滑动轴承内部压力分布及承载能力的影响.结果表明:轴承的几何构型和滑动速度对轴承的性能影响很大,对于相同长度的轴承,气体的峰值压力与轴承的承载能力随轴承出口尺寸的减小和滑动速度的增大而增大;当轴承的几何形状和滑动速度固定时,通道壁温和环境压力是影响轴承性能的重要因素,壁温越高,轴承的承载能力越强;环境压力不同,轴承性能亦有所不同. 相似文献
19.
20.
油酸/PS/TiO_2复合纳米微球对液体石蜡抗磨性能的影响研究 总被引:1,自引:0,他引:1
采用种子乳液聚合法制备了油酸 / PS/ Ti O2 复合纳米微球 ,在四球摩擦磨损试验机上考察了油酸 / PS/ Ti O2 复合纳米微球添加剂对液体石蜡抗磨性能的影响 ,采用 X射线光电子能谱分析了钢球磨斑表面边界膜元素的组成及化学状态 .结果表明 ,油酸 / PS/ Ti O2 复合微球作为润滑油添加剂具有良好的抗磨性能 ,能显著提高基础油的失效载荷 .表面分析结果表明 ,复合纳米微球的抗磨作用取决于其摩擦化学反应所生成的含有 Ti O2 及部分添加剂分解产物的复合膜 . 相似文献