scholarly journals Positioning Accuracy Determination of the Servo Axes for Grinding Wavy-Tilt-Dam Seals Using a Four-Axis Grinder

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 388
Author(s):  
Guang Feng ◽  
Xiaobao Ma
Keyword(s):  
Nuclear Reactor ◽  
Geometric Model ◽  
Implementation Strategies ◽  
Manufacturing Cost ◽  
Positioning Accuracy ◽  
Positioning Errors ◽  
Homogeneous Transformation Matrix ◽  
Manufacturing Techniques ◽  
Multi Body ◽  
Accuracy Determination

The wavy-tilt-dam (WTD) seal is considered to be one of the ideal sealing patterns used in nuclear reactor coolant pumps (RCPs). Grinding such seals with a four-axis grinder had been proposed and six grinding implementation strategies were described in our previous studies. However, another important issue is to determine the positioning accuracy of each servo axis so that the high-precision moving components can be selected properly. In the present paper, the positioning accuracy analysis is carried out to seek a balance between the manufacturing cost and the accuracy requirements. First, a geometric model is established for investigating the error sensitivity of each axis and setting reasonable accuracy allocation of the four axes. Subsequently, the combined influence of all four axes is assessed based on multi-body system (MBS) theory and homogeneous transformation matrix (HTM). According to the results calculated, positioning errors of the X-axis, Z-axis, B-axis, and C-axis within ±10 μm, ±0.1 μm, ±1 arcsec and ±60 arcsec are acceptable, respectively. Meanwhile, the form error calculated of the ground wavy face is no more than 109.74 nm. It is indicated that the accuracy level of the moving components is achievable by modern manufacturing techniques. The present paper is expected to serve as a theoretical basis for the design and development of the four-axis grinder.

scholarly journals Lightweight and maintainable rotary-wing UAV frame from configurable design to detailed design

2021 ◽  
Vol 13 (7) ◽  
pp. 168781402110349
Author(s):  
Huiqiang Guo ◽  
Mingzhe Li ◽  
Pengfei Sun ◽  
Changfeng Zhao ◽  
Wenjie Zuo ◽  
...  
Keyword(s):  
Design Method ◽  
Geometric Model ◽  
Optimization Method ◽  
Frame Structure ◽  
Manufacturing Cost ◽  
Detailed Design ◽  
High Manufacturing Cost ◽  
The Military ◽  
Rotary Wing ◽  
Novel Design

Rotary-wing unmanned aerial vehicles (UAVs) are widespread in both the military and civilian applications. However, there are still some problems for the UAV design such as the long design period, high manufacturing cost, and difficulty in maintenance. Therefore, this paper proposes a novel design method to obtain a lightweight and maintainable UAV frame from configurable design to detailed design. First, configurable design is implemented to determine the initial design domain of the UAV frame. Second, topology optimization method based on inertia relief theory is used to transform the initial geometric model into the UAV frame structure. Third, process design is considered to improve the manufacturability and maintainability of the UAV frame. Finally, dynamic drop test is used to validate the crashworthiness of the UAV frame. Therefore, a lightweight UAV frame structure composed of thin-walled parts can be obtained and the design period can be greatly reduced via the proposed method.

scholarly journals Thermo-hydraulic Simulation of AP1000 Nuclear Reactor Fuel Assembly

2021 ◽  
Vol 31 (1) ◽  
pp. 60-71
Author(s):  
Leonardo Acosta Martínez ◽  
Carlos Rafael García Hernández ◽  
Jesus Rosales García ◽  
Annie Ortiz Puentes
Keyword(s):  
Fuel Assembly ◽  
Power Distribution ◽  
Capital Investment ◽  
Nuclear Power ◽  
Nuclear Reactor ◽  
Geometric Model ◽  
Modular Construction ◽  
Construction Time ◽  
Hydraulic Simulation ◽  
In Series

One of the challenges of future nuclear power is the development of safer and more efficient nuclear reactor designs. The AP1000 reactor based on the PWR concept of generation III + has several advantages, which can be summarized as: a modular construction, which facilitates its manufacture in series reducing the total construction time, simplification of the different systems, reduction of the initial capital investment and improvement of safety through the implementation of passive emergency systems. Being a novel design it is important to study the thermohydraulic behavior of the core applying the most modern tools. To determine the thermohydraulic behavior of a typical AP1000 fuel assembly, a computational model based on CFD was developed. A coupled neutronic-thermohydraulic calculation was performed, allowing to obtain the axial power distribution in the typical fuel assembly. The geometric model built used the certified dimensions for this type of installation that appear in the corresponding manuals. The thermohydraulic study used the CFD-based program ANSYS-CFX, considering an eighth of the fuel assembly. The neutronic calculation was performed with the program MCNPX version 2.6e. The work shows the results that illustrate the behavior of the temperature and the heat transfer in different zones of the fuel assembly. The results obtained agree with the data reported in the literature, which allowed the verification of the consistency of the developed model.

scholarly journals Intelligent Calibration of a Heavy-Duty Mechanical Arm in Coal Mine

Electronics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1186
Author(s):  
Yunhong Jia ◽  
Xiaodong Zhang ◽  
Zhenchong Wang ◽  
Wei Wang
Keyword(s):  
Extreme Learning Machine ◽  
Coal Mine ◽  
Absolute Error ◽  
Calibration Method ◽  
Heavy Duty ◽  
Maximum Absolute Error ◽  
Positioning Accuracy ◽  
Positioning Errors ◽  
Roof Bolter ◽  
Learning Machine

Accurate positioning of an airborne heavy-duty mechanical arm in coal mine, such as a roof bolter, is important for the efficiency and safety of coal mining. Its positioning accuracy is affected not only by geometric errors but also by nongeometric errors such as link and joint compliance. In this paper, a novel calibration method based on error limited genetic algorithm (ELGA) and regularized extreme learning machine (RELM) is proposed to improve the positioning accuracy of a roof bolter. To achieve the improvement, the ELGA is firstly implemented to identify the geometric parameters of the roof bolter’s kinematics model. Then, the residual positioning errors caused by nongeometric facts are compensated with the regularized extreme learning machine (RELM) network. Experiments were carried out to validate the proposed calibration method. The experimental results show that the root mean square error (RMSE) and the mean absolute error (MAE) between the actual mast end position and the nominal mast end position are reduced by more than 78.23%. It also shows the maximum absolute error (MAXE) between the actual mast end position and the nominal mast end position is reduced by more than 58.72% in the three directions of Cartesian coordinate system.

Simulation Analysis and Structure Optimum Design of the High Speed Conveying Manipulator Based on ADAMS

2014 ◽  
Vol 945-949 ◽  
pp. 121-126 ◽  
Author(s):  
Feng Wei Xue ◽  
Ji Ping Zhou
Keyword(s):  
Production Line ◽  
High Speed ◽  
Design Theory ◽  
Simulation Analysis ◽  
Structural Characteristics ◽  
Transmission System ◽  
Manufacturing Cost ◽  
Body Dynamics ◽  
Virtual Prototyping Technology ◽  
Multi Body

The conveying manipulator is an indispensable transmission system of JM31-160 automatic stamping production line, and structural characteristics of the manipulator directly affect the productivity of auto stamping production line. Using virtual prototyping technology, basing on the Multi-body dynamics theory, explored the technical line of dynamic design theory to apply on the transmission system. Reaching a conclusion the function of optimized structure is improved, and manufacturing cost brings down.

On the Optimized Design of Broaching Tools

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
A. Hosseini ◽  
H. A. Kishawy
Keyword(s):  
Cutting Forces ◽  
Cutting Tool ◽  
Metal Removal ◽  
Removal Rate ◽  
Geometric Model ◽  
Design Procedure ◽  
Tool Geometry ◽  
Manufacturing Cost ◽  
Force Model ◽  
Optimized Design

Among the cutting tools that are utilized in industry broaching tools are the most expensive ones. Unlike other machining operations such as milling and turning in which a cutting tool can be used for producing a variety of shapes, the broaching tools are uniquely designed depending on the desired profile to be produced on the workpiece. Consequently, the shape of broaching tools may be altered from one case to the others. This shape can be a simple keyway or a complicated fir tree on a turbine disk. Hence, a proper design of the broaching tools has the highest priority in broaching operation. Every single feature of these expensive tools must be accurately designed to increase productivity, promote part quality and reduce manufacturing cost. A geometric model of the cutting tool and a predictive force model to estimate the cutting forces are two fundamental requirements in simulation of any machining operation. This paper presents a geometric model for the broaching tools and a predictive force model for broaching operations. The broaching tooth is modeled as a cantilevered beam and the cutting forces are predicted based on the energy spent in the cutting system. A design procedure has been also developed for identification of the optimized tool geometry aiming to achieve maximum metal removal rate (MRR) by considering several physical and geometrical constraints.

Joint Modeling and Simulation of the Spindle System of Hammer Crusher Based on Finite Element Analysis and Flexible Multi-Body Dynamics. Part1: Modeling

2012 ◽  
Vol 630 ◽  
pp. 291-296
Author(s):  
Yu Wang ◽  
En Chen ◽  
Jun Qing Gao ◽  
Yun Feng Gong
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
System Simulation ◽  
Geometric Model ◽  
Body System ◽  
Element Analysis ◽  
Spindle System ◽  
Body Dynamics ◽  
Multi Body ◽  
The Impact

In the past finite element analysis (FEA) and multi-body system simulation (MBS) were two isolated methods in the field of mechanical system simulation. Both of them had their specific fields of application. In recent years, it is urgent to combine these two methods as the flexible multi-body system grows up. This paper mainly focuses on modeling of the spindle system of hammer crusher, including geometric model, finite element model and multi-body dynamics (MBD) model. For multi-body dynamics modeling, the contact force between hammer and scrap steel was discussed, which is important to obtain the impact force. This paper also proposed how to combine FEA and MBS to analyze the dynamic performance of the spindle system by using different software products of MSC.Software.

scholarly journals Analysis of a Biomechanical Model for Safe Lifting Using Matlab Simulation

2012 ◽  
pp. 294-299
Author(s):  
Neeraj Saraswat ◽  
Shikhar Sharma ◽  
Rahul Jain ◽  
Deepak Pathak
Keyword(s):  
Material Handling ◽  
Geometric Model ◽  
Reaction Force ◽  
Biomechanical Model ◽  
Force Balance ◽  
Matlab Simulation ◽  
Load Shape ◽  
Moment Load ◽  
Multi Body ◽  
Biomechanical Factors

This paper describes the development of a multi-body biomechanical model that can be used to assess the risk of low back disorders. A multi-segment link model is considered in this paper which represents a human body in which links represent various limbs such as arms, leg, foot, thigh, thorax etc. Force balance and moment balance equations are formed at different joints. Equations formed are written in form of a MATLAB program to determine the relationship between load lifted and muscle moment generated due to load. This biomechanical model was employed to clarify the role of various biomechanical factors such as magnitude of load, shape, size and location of load involved in the load lifting process. To determine safe lifting postures on the basis of model such that the reaction force at the L4 / L5 joint is minimum subjected to other joints not being overstressed is carried out. Various moment-load relationships between various joints are computed along with momentmoment relationships between various joints. The model is able to suggest the safe posture in manual material handling tasks. A geometric model for simulations of postural control is obtained with Matlab/Simulink software .

Theoretical Basis of Generation of Face Worm Gear Drive With Duplex Worm

2006 ◽  
Author(s):  
Andrzej Gessner
Keyword(s):  
Geometric Model ◽  
Single Point ◽  
Worm Gear ◽  
Manufacturing Cost ◽  
Main Role ◽  
Cnc Milling ◽  
Special Equipment ◽  
Gear Drive ◽  
Shaping Process ◽  
The Face

New type of face worm gear drive with double-lead worm is proposed. The advantages of that gear in comparison to contemporary known gears are also mentioned. The shaping process of the face worm gear is carrying out by means of a single point tool. The same insert is used for cutting the duplex worm. Using a single point tool instead of hobbing cutter considerably reduces the manufacturing cost, in which the share of tool production plays the main role. The shaping process is performed on a CNC milling machine with or without additional equipment. Two main methods of shaping depended on setting up the tool machine are presented. One of them requires no special equipment but a single point tool with insert of specific tool included angle, whilst the second uses a constructed tooling. There are also described 3 methods of shaping the face toothing, which depends on the used technology. Geometry of that face worm gear drive is presented and described. The tooth depth is constant along the whole tooth line. Nominal width of tooth section as well as its location depends on the lead difference of the worm. Provided scheme can be used to calculate those parameters. The total length of the duplex worm is calculated by taking into consideration the internal and external diameters of the worm gear and the additional length which is needed to reduce the backlash. The shape and size of the single point tool is determined according to the worm and the necessary geometric model is provided. There are also given criteria, which limit the maximum length of worm and its maximum lead angle. A complete algorithm describing the designing process of that type of gear is presented in the final part of the article.

Design of Flexible Membrane Fixture for Automobile Door-Trim Infra Stake Welding Machine

2019 ◽  
Author(s):  
Hong-Seok Park ◽  
Khash-Ochir Namjil
Keyword(s):  
New Technology ◽  
Geometric Model ◽  
Elastic Behaviour ◽  
Manufacturing Cost ◽  
Size Change ◽  
Element Analysis ◽  
Rubber Sheet ◽  
Flexible Membrane ◽  
The Finite Element Analysis ◽  
Parts Manufacturing

Abstract Flexible membrane fixture is new technology which can adapt to the workpiece shape and size change, such as automobile door-trim parts manufacturing. Due to the use of flexible membrane fixture, significantly reducing manufacturing cost and replacing fixture time. In this paper, the design of the flexible membrane fixture is generated, and the application is showed in a case. Natural rubber sheet used as a flexible membrane. The membrane inflation model generated by ANSYS using Mooney-Rivlin method and its simulation result compared with the experiment result. The door-trim model developed by AUTODESK INVENTOR modelling software. This 3-D geometric model was imported to using ANSYS Workbench 18.2. The Finite element analysis was done after assigning loading and boundary conditions. The applied load considered for this analysis is the pressure applied to the membrane while the door-trim clamped by side clamps. The result shows that Flexible membrane fixture has higher flexibility and fixtured door-trim has smaller deformation value than company requirement. Through comparing the design results, it is found that flexible membrane fixture has higher elastic behaviour.

Analysis of Static Stability of Articulated Hydraulic Excavator with Two Degree of Freedom

2012 ◽  
Vol 430-432 ◽  
pp. 1663-1666
Author(s):  
De Xin Sun ◽  
Xin Hui Liu
Keyword(s):  
Working Conditions ◽  
Geometric Model ◽  
Static Stability ◽  
Degree Of Freedom ◽  
Hydraulic Excavator ◽  
Lateral Stability ◽  
Dynamic Software ◽  
Multi Body ◽  
Two Degree Of Freedom ◽  
Body Dynamic

In this paper, the geometric model of the hydraulic excavator with two degree of freedom was built, and then the dynamic model based on the multi-body dynamic software RecurDyn was built, and then the lateral stability and longitudinal stability of the hydraulic excavator on different gradients were analyzed, the result showed the tipping feather of the hydraulic excavator truly, and this paper provides guidance for choosing the hydraulic excavator’s working conditions.

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