Tài liệu miễn phí Cơ khí - Chế tạo máy

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Thiết kế và chế tạo máy sản xuất đĩa đựng thức ăn từ mo cau

Bài viết trình bày thiết kế và sản xuất máy được sử dụng để sản xuất các đĩa đựng thức ăn từ mo cau. Những tấm này được làm từ chất thải nông nghiệp thay vì vật liệu nhựa.

12/29/2020 6:08:08 PM +00:00

Tổng hợp câu hỏi thi kết thúc môn Tự động thủy khí

Tổng hợp câu hỏi thi kết thúc môn Tự động thủy khí được biên soạn nhằm cung cấp đến các bạn sinh viên với 30 câu hỏi hỗ trợ cho quá trình ôn luyện và củng cố kiến thức hoàn thành các bài thi gặt hái nhiều thành công.

12/29/2020 5:40:06 PM +00:00

Kiểm tra sát hạch kết thúc khóa đào tạo nghề Hàn (Cơ khí)

Kiểm tra sát hạch kết thúc khóa đào tạo nghề Hàn (Cơ khí) được biên soạn với 20 bài tập trắc nghiệm có kèm theo đáp án hỗ trợ các bạn trong quá trình ôn luyện, củng cố kiến thức chuẩn bị tốt cho kì thi sát hạch kết thúc khóa đào tạo nghề Hàn.

12/29/2020 4:23:57 PM +00:00

Ảnh hưởng của một số thông số chế độ cắt đến độ nhám bề mặt gia công trên máy tiện

Bài viết giới thiệu kết quả nghiên cứu xác định ảnh hưởng của một số thông số chế độ cắt trong gia công tiện trên thiết bị thông dụng là máy tiện T18A.

12/29/2020 4:12:19 PM +00:00

Nghiên cứu ảnh hưởng của lực chặn phôi đến khả năng tạo hình thủy cơ thép không gỉ trên cơ sở mô phỏng số

Bài viết này nhằm mục đích nghiên cứu khả năng tạo hình biến dạng dẻo của thép không gỉ SS304 ở nhiệt độ phòng bằng phương pháp dập thủy cơ.

12/29/2020 4:10:38 PM +00:00

Dynamic crack propagation in specimens with a surface irregularity

The main purpose of the present work is to modify and enhance the existing fatigue rig which can be used to perform fatigue experiments on different sections including pipe sections. The structure of this paper is as follows. Section 2 describes the experimental setup used for the fatigue rig, describing the original design and current modifications which includes introducing two new load cells, plastic rollers and sliding flexible jaws to accommodate wide range of section sizes and shapes. Then we describe the instrumentation and data acquisition.

12/29/2020 1:59:58 PM +00:00

Misattributions and misnomers in mechanics: Why they matter in the search for insight and precision of thought

The purpose of this article is to bring some examples of misattributes (i.e., theories and models that bear some one’s name while the idea belongs to someone else) and misnomers (i.e., words or phrases that are either incorrect or inaccurate) to the attention of the colleagues in the field, and correct them so that these incorrect phrases and attributions and misnomers are not repeated in the future writings. In the process, we also discuss the purpose of a literature reviews and the need for precision of thought in naming ideas or concepts. It is hoped that people will be careful and precise in using the words, names, and phrases correctly (since after all, these represent ideas that need to be communicated) and not propagate inaccurate information in the literature. The discussion presented is restricted to mostly structural and computational mechanics.

12/29/2020 1:59:45 PM +00:00

Asymptotic theory for thin two-ply shells

This paper develop an asymptotic model for the finite-deformation, small-strain response of thin laminated shells composed of two perfectly bonded laminae that exhibit reflection symmetry of the material properties with respect to an interfacial surface. No a priori hypotheses are made concerning the kinematics of deformation. The asymptotic procedure culminates in a generalization of Koiter’s well-known shell theory to accommodate the laminated structure, and incorporates a rigorous limit model for pure bending.

12/29/2020 1:59:26 PM +00:00

Accurate through-the-thickness stress distributions in thin-walled metallic structures subjected to large displacements and large rotations

The present paper presents the evaluation of three-dimensional (3D) stress distributions of shell structures in the large displacement and rotation fields. The proposed geometrical nonlinear model is based on a combination of the Carrera Unified Formulation (CUF) and the Finite Element Method (FEM). Besides, a Newton-Raphson linearization scheme is adopted to compute the geometrical nonlinear equations, which are constrained using the arc-length path-following method.

12/29/2020 1:59:01 PM +00:00

Optimal parameters of dynamic vibration absorber for linear damped rotary systems subjected to harmonic excitation

The performance of the proposed optimal DVA is compared with that obtained by existing optimal solution in literature. It is shown that the proposed optimal parameters are possible to obtain superior vibration suppression compared to existing optimal formula. Extended simulations are carried out to examine the performance of the optimally designed DVA and the sensitivity of the optimum parameters. The simulation results show that the improvement of the vibration performance on damped rotary system can be as much as 90% by using DVA.

12/29/2020 1:58:51 PM +00:00

Design and analysis of a displacement sensor-integrated compliant microgripper based on parallel structure

This study evaluates the displacement sensitivity of a new compliant microgripper. The microgripper is designed based on a four-bar mechanism and the concept of a compliant mechanism. The effects of the width of the right circular hinge, the thickness of microgripper, and the material properties on the dis-placement sensitivity are considered via using the finite element method. In the beginning, the stress and deformation of the compliant microgripper are evaluated.

12/29/2020 1:58:36 PM +00:00

Tự học Solidworks 2020

Tự học Solidworks 2020 thông tin đến các bạn với các nội dung giới thiệu tổng quan về Solidworks; môi trường phác thảo - Sketcher; thiết kế 3D – Part; môi trường lắp ráp chi tiết – Assembly; bản vẽ chi tiết– Drawing.

12/29/2020 1:20:09 PM +00:00

Algorithm for improving feeding rates of industrial welding robot TA 1400

An algorithm for improving feeding rates of industrial welding robot TA 1400 of Panasonic with 6 degrees of freedom is presented. The kinematics and dynamics of the robot are calculated on MATLAB software. The proposed algorithm for improving feeding rates is mathematically analyzed and the performance of the system is evaluated in a simulation environment. The simulation results are used for proving the efficiency of the solution. Based on the achieved results, the algorithm can be applied for reducing time and improving the productivity of other industrial robots in the future.

12/29/2020 1:03:27 PM +00:00

Nghiên cứu thiết kế tối ưu hóa hộp số máy kéo Thaco

Bài viết trên cơ sở sử dụng phần mềm tính toán mô phỏng Unigraphics NXCAD và SIMCENTER do tập đoàn Siemens AG cung cấp, chúng tôi đã tiến hành phân tích, lựa chọn hợp lý cấu hình hệ thống truyền lực của máy kéo Thaco bao gồm cụm hộp số chính, cầu chủ động, các cụm khác, và tính toán các tỷ số truyền hợp lý của hệ thống truyền lực máy kéo.

12/29/2020 12:12:26 PM +00:00

Điều khiển tàu định vị động dùng mô hình nội

Bài viết xác định các điều kiện ổn định bền vững của hệ thống điều khiển đối với sai số mô hình. Một trong ưu điểm của bộ điều khiển đề xuất là có thể chỉnh định tính bền vững của hệ kín bằng một tham số. Hệ thống điều khiển đề nghị cũng được so sánh với hệ thống điều khiển PID. Hệ điều khiển PID có nhiều ưu điểm, tuy nhiên để chỉnh định các tham số cần tốn nhiều thời gian và năng lượng.

12/29/2020 12:06:41 PM +00:00

Using an LQR active anti-roll bar system to improve road safety of tractor semi-trailers

Tractor semi-trailer vehicles are playing an increasingly important role in the global freight chain. However, due to the heavy total load and height of the center of gravity, this type of vehicle is often at a higher risk of instability than other vehicles. This paper focuses on improving the vehicle roll stability by using an active anti-roll bar system.

12/29/2020 12:01:54 PM +00:00

The effects of the process parameters in electrochemical machining on the surface quality

Based on the number of previous studies, this study aims to investigate the effects of process parameters of an Electrochemical Machining process which are electrolyte concentration, voltage applied to the machine, feed rate of the electrode and Inter-Electrode Gap between tool and work - piece. Aluminum samples of 25 mm diameter x 25 mm height and 30mm diameter x 25mm height of the tool is made up of copper with a circular cross section with 2 mm internal hole. The design of the system is based on the Taguchi method.

12/29/2020 12:00:25 PM +00:00

Study on the radial clearance of the screw conveyor for transporting cement

In this paper, the cement is transported by screw conveyor. The experiment is done with different parameters such as speed of rotation and the radial clearance. The productivity is recorded with each change of parameters. The result from the experiment will predict the best radial clearance to transport the cement. The paper will conclude the area having high productivity and low productivity.

12/29/2020 11:59:41 AM +00:00

Study on analysis and design of an VIAM- AUV2000 autonomous underwater vehicle (AUV)

This paper presents the design of the VIAM-AUV2000 autonomous underwater vehicle (AUV) with a built-in cylinder for floatation and counterbalance. The modular structure including mechanical design, electronic system, and control algorithm ensures continuous operation for the vehicle at a depth of 50 meters underwater.

12/29/2020 11:59:22 AM +00:00

Study of design and manufacture for one-line rice color sorting machine

This paper proposes the design calculation determining parameters of the relative distance for a standard working mode and make the gap adjustment mechanism for the color rice separator machine can best respond the part of the image recognition camera control.

12/29/2020 11:59:14 AM +00:00

Simulation study on polishing of gear surfaces in non-Newtonian fluid

The influence of the inclination angles on the pressure distribution and characteristics of fluid flow was performed by simulation process. The inclination angles of 0, 4, 8, 12, 16, 20 and 24 degrees were chosen in this study.

12/29/2020 11:58:58 AM +00:00

Optimal dynamic routing for 2 forklifts in narrow-aisle racking warehouse

This paper contribute by constructing an algorithm base on dynamic routing strategy to solve the problem. Storage location is determine by the Closest Open Location algorithm - COL and collision is solved through the time windows concept.

12/29/2020 11:57:40 AM +00:00

Numerical investigation of the thermocapillary migration of a water droplet in a microchannel by applying heat source

In this study, the numerical computation is used to investigate the transient thermocapillary migration of a water droplet in a micro-channel under the effect of heating source. For tracking the evolution of the free interface between two immiscible fluids, we employed the finite element method with the two-phase level set technique to solve the Navier-Stokes equations and continuity equation coupled with the energy equation. Both the upper wall and the bottom wall of the microchannel are set to be an ambient temperature.

12/29/2020 11:57:18 AM +00:00

Modeling, design and control of low-cost remotely operated vehicle for shallow water survey

This paper presents the research on design and control of Remotely Operated Vehicle (ROV) belonging to National key Laboratory of Digital Control and System Engineering. Basically, it is controlled by human pilots to move underwater and perform specifically pre-assigned tasks. T he power supply and communication channel for the vehicle are connected from an onshore station via cable systems. There are several stages of the pipeline in implementing a full-scale ROV platform that must be studied carefully.

12/29/2020 11:57:02 AM +00:00

Methodology for scaling finite element dummy and validation of a Hybrid III dummy model in crashworthiness simulation

For study of car-pedestrian crashes, it is two common methods that can be employed: conducting crash tests with mechanical dummies and simulating car crashes on computer. The former is a traditional way and gives good results compared with real life car impact; however, its disadvantage is very expensive test equipment and generally more time-consuming than the latter because after every crash test, experimental vehicles as well as dummies need repairing to be ready for the next experiments.

12/29/2020 11:56:54 AM +00:00

Experimental study of circular inlets effect on the performances of Gas-Liquid Cylindrical Cyclone separators (GLCC)

The main target of the current study is to deeply understand the effect of different geometrical configurations of the circular inlet on performances of GLCC by the experimental method for two phases flow (gas-liquid). Two different inlet configurations are constructed, namely: One circular inlet and two symmetric circular inlets. As a result, we propose the use of two symmetric circular inlets to enhance the separator efficiency because of their effects.

12/29/2020 11:55:36 AM +00:00

Effects of Minimum Quantity Lubrication (MQL) on cutting temperature, tool wear and surface roughness in turning AISI-1045 material

This research focus on to presents of the MQL parameters optimization approach in which the multi-response outputs based on Taguchi's L9 orthogonal array method is used. During the turning AISI-1045 steel, the cutting temperature, the maximum of tool wear, and the surface roughness were measured. The MQL parameters which are ratio of soluble lubricant and water, pressure of spray head, flow volume of emulsion was simultaneously optimized by taking the multi-response outputs using Taguchi based grey relational analysis (GRA) into consideration. In turning experiments, three different flow volume of emulsion Q (40, 60, 80 ml/h), three different levels pressure of spray head P (3, 5, 7 bar) and three different levels ratio of soluble lubricant and water R (4, 6, 8%) were used. Beside, three mathematical models were created using response surface regression methodology.

12/29/2020 11:55:03 AM +00:00

Design, implementation and evaluation for a high precision prosthetic hand using MyoBand and Random Forest algorithm

A prosthesis is an equipment provided to people who lost one or some parts of their limbs to help them having almost normal behaviors in daily or hard activities. The convenience and intelligence of devices should create easiness and flexibility for users. Artificial devices require interdisciplinary collaboration from neurosurgeons, surgical surgeons, physiotherapists and equipment development. Computer engineering plays a crucial role in the design step, supporting manufacturing, training and recognition to match the desirability of customers. Moreover, users need a wide range of different options such as an aesthetic functional material, a myoelectric mechanism, a body-powered appliance or an activity specified device.

12/29/2020 11:54:18 AM +00:00

Design and fabrication of wave generator using an oscillating wedge

This paper describes the design and fabrication of a wave flume. The wave maker is made by a triangle wedge. Wave flume size is 0.75(m) in width, 1.3(m) in height and 11(m) in length. The characteristic of a generation wave is also conducted in this research. An experimental results of the crated wave is considered by two operation parameters (Eccentricity and Rotation speed). Wave flume is equipped with a triangle wedge which located at one end of the wave flume, and it can be move along the rail of the wave flume.

12/29/2020 11:53:47 AM +00:00

Deriving formulations for forecasting the ultimate strength of locally dented ring-stiffened cylinders under combined axial compression and radial pressure loads

This paper focuses on the derived equations to evaluate the ultimate strength of ring-stiffened cylinders with local denting damage under combined loadings. The damage generation scenarios in this research are representing the collision accidents of offshore stiffened cylinders with supply ships.

12/29/2020 11:53:40 AM +00:00