基于ANSYS/UG对企业某系列滚筒洗衣机包装顶盖的改进设计

使用UG建立合适的模型设计,同时运用 ANSYS有限元软件,对滚筒洗衣机台面板进行应力仿真分析,获得最大应力分布规律,在此基础并根据实验和售后数据,改进了原顶盖的结构,它能够分散台面板受到的集中应力,降低滚筒洗衣机台面板变形、破损等问题,为企业提高经济效益.     

滚筒洗衣机瞬态脱水阶段控制策略的研究

滚筒洗衣机在瞬态脱水阶段的振动较为剧烈,为此制定脱水启动阶段电机转速的两种控制策略来实现滚筒洗衣机的减振降噪。首先,在动力学仿真软件ADAMS中建立滚筒洗衣机动力学模型,分析脱水工况下启动加速度以及偏心负载质量对瞬态脱水振动的影响。进而,依据瞬态脱水振动特点制定两种控制策略:分段式加速的开环控制策略以及基于传感器测振的闭环控制策略。最后,建立ADAMS与Simulink联合控制仿真模型,对比研究传统加速方式工况下以及两种控制策略下滚筒洗衣机瞬态脱水阶段的振动情况。结果表明这两种控制策略在瞬态脱水阶段对滚筒洗衣机具有良好的抑振作用。     

基于边界单元法的印刷机滚筒结构刚度分析

以实际滚筒模型为分析对象,使用边界单元法(BEM)对该结构进行刚度计算和分析。通过数值算例验证了BEM的正确性和有效性,在此基础上,充分考虑实际工况,应用BEM法分析滚筒在重力作用下的自由变形,并与基于FEM的商用结构分析软件得到的结果进行对比。对比结果显示,BEM法在分析滚筒结构刚度时具有精度高、计算量小以及纯边界离散等特点,是一种应用于结构刚度分析的高效方法。     

某工业洗衣机动力学特性研究

工业洗衣机在高速脱水的工作过程中,由于衣物的不均匀分布而产生偏心激振力,造成整体结构剧烈振动,从而存在结构疲劳破坏的事故隐患。针对某型工业洗衣机的结构特点建立有限元模型,对洗衣机在高速脱水工况下偏心激振力的大小和分布规律进行分析。运用NASTRAN软件计算得到的结构瞬态响应分析结果,与振动测试结果对比吻合较好。本研究对工业洗衣机的疲劳强度分析与结构优化具有重要意义。     

滚筒洗衣机机箱动态特性分析

结合实验模态与有限元理论模态分析，对滚筒洗衣机的机箱进行振动特性分析。首先，采用有限元软件ANSYS理论模态分析对机箱进行模态求解，得到计算模态参数;另外，用脉冲激励法对机箱进行模态实验，得到实验模态参数。通过比较理论模态与实验模态参数，结果表明吻合较好。基于对机箱固有特性的分析，提出机箱结构动态特性修改方案，并通过理论验证，说明改进后机箱的振动特性得到了明显的改善。     

前开式滚筒洗衣机噪声评定方法初探

从滚筒洗衣机结构与运行过程的力学特性出发,结合滚筒洗衣机噪声测量的结果,发现了衣物随机形成的不平衡质量是滚筒洗衣机噪声测试结果具有不确定性的原因.这些随机的不平衡质量在洗衣机运行过程中产生了随转速变化的离心力激起洗衣机的随机振动,并引发随机的噪声.为此,提出了改进滚筒洗衣机噪声测量与评价方法的建议.     

印刷机滚筒动态性能的研究

结合转子的平衡理论,以J2108胶印机的压印滚筒为研究对象,对印刷机滚筒进行动平衡研究.根据滚筒的结构特点,对其进行适当的简化,运用有限元分析软件ANSYS进行建模与分析,最终得到滚筒不平衡的相关数据和信息,为实际生产中滚筒进行动平衡提供参考.     

印刷机滚筒的模态分析

印刷机滚筒的结构和动态性能对印刷机工作特性有很大影响,为提高印刷机的印刷质量,以纸箱印刷机滚筒为研究对象,在已有优化设计的基础上,利用ANSYS有限元分析软件,对优化前后的纸箱印刷机滚筒进行了模态分析,得到了印刷机滚筒的固有频率和振型,从动态特性上为静态优化结果提供了支持。     

基于Pro/Mechanica的印版滚筒体有限元模态分析

叙述了用Pro/Mechanica软件对印版滚筒体进行前2阶模态分析的过程,根据分析结果,计算出了印版滚筒体的前2阶固有频率和振型。与滚筒齿轮的啮合频率比较,判断了滚筒的工作特性,为印版滚筒体的振动特性分析、振动故障诊断和预报以及结构动力特性的优化设计提供了依据。     

双回程烘干滚筒结构强度有限元分析

双回程烘干滚筒在运行一定时间后,容易在进料端滚圈支撑板处出现开裂现象。通过分析物料在滚筒内的分布情况,并对滚筒运行工况进行合理简化,利用有限元分析软件ANSYS对滚筒进行静强度分析,并与实际情况进行对比,确定滚筒应力集中区域,研究滚圈支撑板开裂的原因。     

斜筒式滚筒洗衣机工作变形与低频噪声分析

利用工作变形分析技术,研究了某款斜筒式滚筒洗衣机脱水工作过程低频段(7-600Hz)的振动变形,结合噪声量测分析手段,对振动和低频噪声的关联特性进行初步探讨。结果表明,脱水工作过程中电机、滚筒等部件的运动不平衡力及电机的电磁激振力是整机振动主要原因;低频噪声主要由洗衣机结构对电机激励的振动响应所致,两侧壁辐射的噪声明显高于前后方向。低频噪声的控制可以通过改变结构的振动响应特性实现。     

Optimization of washing machine kinematics,dynamics, and stability during spinning using a multistep approach

The vibrations originating from badly distributed load inside the drum are in this paper channeled into cost functions which are used as objectives for optimization. The defined kinematic cost function deals with performance of tub motion and can ensure margins to collision of parts inside the washing machine or constitute a step in the process to increase the machine capacity. The dynamic cost function measures transmitted vertical force to the hosting structure. Forces which cause noise and vibration impact on the surroundings. Two different cost functions for stability of a washing machine in the sense of walking avoidance are also presented. The difference between these formulations is studied with an example, which shows that although it is costly to evaluate the second formulation it will give more freedom to find good washing machine designs. Three different applied problems which aim to optimize different suspension designs for new and existing washing machines are presented. For effective numerical computation of the complex multiobjective optimization problems a multistep approach for washing machine structural optimization is presented. With the help of parallel calculation of the response of dynamic models implemented in Adams?View, the approach has been used to solve the presented problems. Results derived from the solution to the optimization problems have been used in development of new washing machines which afterwards have been put on the market.     

Modeling the Dynamics of Fabric in a Rotating Horizontal Drum Using the Discrete Element Method

In order to provide a tool for designing more efficient methods of mixing fabric, a simplified discrete element computational model was developed for modeling fabric dynamics in a rotating horizontal drum. Because modeling the interactions between actual pieces of fabric is quite complex, a simplified model was developed where individual pieces of bundled fabric are represented by spherical particles. This model is essentially a ball mill. The simulations are used to investigate fabric bundle kinematics, the power required to drive the rotating drum, and the power dissipated through normal and tangential contacts. Parametric studies were performed to investigate the effects of fill percentage, baffles, rotation speed, friction coefficient, and coefficient of restitution. The simulation results indicate that fill percentage, drum rotation speed, and friction coefficient play significant roles in the fabric bundle dynamics. For example, the specific drum power increases by a factor of 600% to 800% as the fill percentage decreases from 75% to 25%. In addition, the maximum specific drum power occurs at a rotation speed just less than the speed at which centrifuging occurs. The friction coefficient does not play a significant role in the bundle dynamics for values greater than a critical value. The critical value decreases from a value of approximately 0.3 at a 25% fill percentage to 0.05 for a 75% fill percentage. For friction coefficients less than this critical value, the specific power decreases with decreasing friction coefficient. Drum baffles have a minor effect on the power dissipation and kinematics for fill percentages greater than 50%. Bundle size and coefficient of restitution have a relatively weak influence on the measured parameters.     

Modeling the Dynamics of Fabric in a Rotating Horizontal Drum Using the Discrete Element Method

In order to provide a tool for designing more efficient methods of mixing fabric, a simplified discrete element computational model was developed for modeling fabric dynamics in a rotating horizontal drum. Because modeling the interactions between actual pieces of fabric is quite complex, a simplified model was developed where individual pieces of bundled fabric are represented by spherical particles. This model is essentially a ball mill. The simulations are used to investigate fabric bundle kinematics, the power required to drive the rotating drum, and the power dissipated through normal and tangential contacts. Parametric studies were performed to investigate the effects of fill percentage, baffles, rotation speed, friction coefficient, and coefficient of restitution. The simulation results indicate that fill percentage, drum rotation speed, and friction coefficient play significant roles in the fabric bundle dynamics. For example, the specific drum power increases by a factor of 600% to 800% as the fill percentage decreases from 75% to 25%. In addition, the maximum specific drum power occurs at a rotation speed just less than the speed at which centrifuging occurs. The friction coefficient does not play a significant role in the bundle dynamics for values greater than a critical value. The critical value decreases from a value of approximately 0.3 at a 25% fill percentage to 0.05 for a 75% fill percentage. For friction coefficients less than this critical value, the specific power decreases with decreasing friction coefficient. Drum baffles have a minor effect on the power dissipation and kinematics for fill percentages greater than 50%. Bundle size and coefficient of restitution have a relatively weak influence on the measured parameters.     

教学型洗瓶机的设计

目的以工业生产用的洗瓶机为基础,设计出适合机电设备类、包装类专业教学实践用的洗瓶机。方法生产中用的洗瓶机生产能力高,但工艺流程复杂,结构庞大。通过分析工业用大型洗瓶机的基本工艺流程及结构,重点掌握教学应用型洗瓶机的瓶子运行路线、进出瓶装置、重要控制点以及其他必要的结构,明确在工业用洗瓶机的基础上改进设计教学型洗瓶机的关键点。结果改进后的洗瓶机重点结构突出,生产能力为600瓶/h,占地尺寸(长×宽)为4100 mm×1800 mm,适合教学使用。结论改进设计生产实践中所使用的大型设备,将其转化成教学型设备,具有生产与教学实践相结合的重要意义。     

Modified drum–buffer–rope scheduling mechanism for a non-identical parallel machine flow shop with processing-time variation

The drum–buffer–rope (DBR) is a scheduling mechanism under the Theory of Constraints (TOC) philosophy. In DBR, ‘drum’ is a production schedule on the capacity-constrained resources (CCRs), which controls the speed of production for the whole system; ‘rope’ is a mechanism to release the required material to the CCRs; and ‘buffer’ is used to protect the CCRs from starvation due to statistical fluctuations. For a non-identical parallel machine flow-shop environment, estimating an efficient rope and time buffer for DBR implementation is not an easy task because of the complexity of non-identical parallel machine loading. This paper proposes a new scheduling method, which is called the modified DBR (MOD-DBR). It applies a backward finite capacity scheduling technique, including machine loadings and detail scheduling, instead of the rope mechanism in DBR. The scheduling performances of MOD-DBR are evaluated under variable processing time situations. The experimental results indicate that the MOD-DBR without a time buffer outperformed the DBR with a considerable level of buffer on the average flow time, while they have the same performance on tardiness, constraint resource utilization, and throughput.     

航空发动机直通型篦齿封严鼓筒气动力分析

鼓筒篦齿是航空发动机风扇部分的重要封严结构,其密封性能极大地影响着航空发动机的整机性能。为了充分认识鼓式篦齿封严结构中齿腔内的压力分布,了解篦齿封严机理,该文采用数值方法对鼓筒篦齿封严流场进行了仿真分析,重点讨论了旋转速度和篦齿封严出口静压对鼓筒表面气动力的影响。仿真结果表明:1)沿着流动方向鼓筒表面静压总体上呈现先减小后增大的变化趋势;2)与旋转速度的变化相比,篦齿封严出口静压的变化对鼓筒表面静压的影响更为显著;3)旋转速度一定时,鼓筒表面静压随着篦齿封严出口静压的增大线性增大。