scholarly journals Deflection Analysis of the Thin-Web Workpiece Structure Using Similarity Concept

2011 ◽  
Vol 337 ◽  
pp. 479-488
Author(s):  
Nurhaniza Mohamad ◽  
M.K.A.M. Arifin ◽  
Aidy Ali ◽  
Faizal Mustapha
Keyword(s):  
High Speed ◽  
High Performance ◽  
Tool Path ◽  
Dynamic Stiffness ◽  
Cutting Parameters ◽  
High Speed Machining ◽  
Workpiece Vibration ◽  
Deflection Analysis ◽  
Optimum Solution ◽  
Element Removal

The thin-web structure component is widely used in aviation and aerospace industries with the reason of light weight and high performance. However, the thin-web components are tending to deflect because of their poor rigidity and the effect of cutting force during cutting process. It is required to perform of high-speed machining that can remove the large number of material in a shorter time in order to allow machining of such structure. The performance of high-speed machining operation is restricted by the static and dynamic stiffness of the tool and part that can cause some problems such as regenerative chatter and ‘push-off’. The tool path plays an important function to avoid the problem occurs as it assists to reduce the workpiece vibration during machining. The optimization of tool path is done by determining the element removal sequences and the materials removal are implemented using milling cutter. The maximum deflection for each element removed is recorded in order to define the optimum solution of element removal sequences. The analysis shows that there are significant effects of workpiece stiffness with relation to the cutting parameters setting.

The Process Strategies of Mould High-Speed Machining and their Applications in the Environment of PowerMILL

2011 ◽  
Vol 188 ◽  
pp. 542-548 ◽  
Author(s):  
Jie Liu
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Cutting Parameters ◽  
Depth Of Cut ◽  
Feed Speed ◽  
Machining Parameters ◽  
High Speed Machining ◽  
Whole Process ◽  
Machining Strategies ◽  
Selection Of

High-speed machining requires the support of high intelligent CAM software as well as customized machining strategies and properly selected machining parameters. Only by combining the two can the advantage of high-speed machining be made full use of. Compared to ordinary NC cutting, high-speed machining has special requirements for process strategies, CAM system and tool path. A complete tool path includes approaching/retracting tool, moving tool and tool path. Based on the above principles, a mould part is successfully processed using the PowerMILL software at the high-speed machining centre of DMG-DMU40T. The maximum hardness of the mould part is HRC50. There’s a 30 degree corner in the cavity with a transition radius of 3mm. The whole process can be divided into three stages: rough, semi-finish and finish machining and each stage involves the selection of tool path, the selection of tool, the selection of cutting parameters (including spindle speed, feed speed and depth of cut), and the application of PowerMILL specific machining methods (such as Race-line machining, rest roughing, automatic trochoidal machining, 3D offset finishing and etc).

Collision-Free Tool Path Generation for Five-Axis High Speed Machining

2011 ◽  
Vol 474-476 ◽  
pp. 961-966 ◽  
Author(s):  
Li Qiang Zhang ◽  
Min Yue
Keyword(s):  
Image Analysis ◽  
Collision Detection ◽  
High Speed ◽  
Tool Path ◽  
Geometric Model ◽  
High Speed Machining ◽  
Analysis Method ◽  
Geometric Information ◽  
Detection Approach ◽  
Five Axis

Collision detection is a critical problem in five-axis high speed machining. Using a combination of process simulation and collision detection based on image analysis, a rapid detection approach is developed. The geometric model provides the cut geometry for the collision detection and records a dynamic geometric information for in-process workpiece. For the precise collision detection, a strategy of image analysis method is developed in order to make the approach efficient and maintian a high detection precision. An example of five-axis machining propeller is studied to demonstrate the proposed approach. It has shown that the collision detection task can be achieved with a near real-time performance.

Investigation and Modeling of Flag Generation in Honeycomb Sandwich Panel Machining

2018 ◽  
Author(s):  
Derek M. Yip-Hoi ◽  
David D. Gill
Keyword(s):  
Geometric Modeling ◽  
High Speed ◽  
Tool Path ◽  
Sandwich Panels ◽  
Cutting Parameters ◽  
Honeycomb Structures ◽  
Anisotropic Mechanical Properties ◽  
Honeycomb Sandwich ◽  
Low Stiffness ◽  
The Impact

Light weight honeycomb structures lend themselves to important applications in aerospace. These range from aerodynamic and structural components such as wing edges, flaps, rotor blades and engine cowlings, to aircraft interior structures such as overhead luggage bins, compartment liners, bulkheads and the monument structures found in galleys and lavatory areas. Often the honeycomb is formed into a composite ply sandwich with fiberglass face sheets bonded to the honeycomb core. These panels are cut to shape using CNC routers and specially designed cutting tools. However, the quality of the cuts generated even with these special tools leaves much to be desired. The low stiffness of the structure leads to imperfections such as fraying of the cut face sheet edges and the generation of flags along the cut honeycomb edge. These impact the ease of assembly and often require manually intensive reworking to mitigate. The cutting of honeycomb structures and sandwich panels is challenging due to low stiffness, anisotropic mechanical properties and a high proportion of interrupted cutting due to the air voids that are present. The cutting mechanics are not well understood at this time. This paper presents findings from the study of cutting of honeycomb sandwich panels using high speed videography and correlates these with results of geometric modeling of the engagement between the cutter and workpiece. The study includes the impact of the trajectory of the tool path through the cell structures on the generation of flagging. It also reports on the effects of two different cutting tool geometries and the introduction of a lead angle on the size and structure of the flags generated. These findings present the case for a research regime similar to the one completed for solid metals, into modeling the mechanics behind machining honeycomb structures. This will help manufacturers using these materials to make better choices in the tools, cutting parameters and machining strategies that they employ in their process planning.

Tool Path Generation Method of Equal Approximation Error for Free-Form Surface in High Speed Machining

2010 ◽  
Vol 102-104 ◽  
pp. 544-549 ◽  
Author(s):  
Chun Jiang Zhou ◽  
Hong Chun Chen
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Cutting Tool ◽  
End Milling ◽  
Approximation Error ◽  
Tool Path Generation ◽  
Free Form ◽  
Path Generation ◽  
High Speed Machining ◽  
Free Form Surface

The development of surface high-speed machining has put forward higher demands for uniform cutting load and smooth cutting tool path. Most current tool-path planning methods are based on constant scallop height, but they have the disadvantage of path point redundancy during the path discretization process. To overcome the problem, a tool path generation method of equal approximation error in each step for free-form surface is presented based on geodesic principle and curvature judgment. In this method, the NURBS curve is employed to realize smooth transition for adjacent two tool paths in high-speed machining. A certain angle of inclination of flat-end milling cutter during multi-axis machining improves the machining efficiency. Because of the advantage of this machining condition, the cutter location point generation algorithm during the machining condition is given by the method. The method is verified and simulated by C++. Experiment results proved that it can obtain uniform cutting load and continuous smooth cutting tool path during surface high-speed machining by the proposed method.

A smooth spiral tool path for high speed machining of 2D pockets

2009 ◽  
Vol 41 (7) ◽  
pp. 539-550 ◽  
Author(s):  
Martin Held ◽  
Christian Spielberger
Keyword(s):  
High Speed ◽  
Tool Path ◽  
High Speed Machining ◽  
Spiral Tool Path

Experimental assessment of the dynamic stiffness of a fault-tolerant fly-by-wire hydraulic actuator

2012 ◽  
Vol 226 (6) ◽  
pp. 679-690 ◽  
Author(s):  
G Di Rito ◽  
R Galatolo
Keyword(s):  
High Speed ◽  
High Performance ◽  
Position Control ◽  
Fault Tolerant ◽  
Dynamic Stiffness ◽  
Feasibility Studies ◽  
Hydraulic Actuator ◽  
Dynamic Interactions ◽  
Flight Controls ◽  
Vibration Tests

The stiffness of an actuator depends on the closed-loop position control (architecture and parameters), on the load frequency, and, for fault-tolerant actuators, on the operative mode. The stiffness response is of basic importance for the design of actuators for primary flight controls, especially for high-performance aircrafts. Actually, during flight conditions characterized by high speed and high angle-of-attack, the dynamic interactions between aircraft structure, actuator, and aerodynamic loads can induce aeroservoelastic effects, which, if not controlled, can imply performance degradation and even instability. The study and the compensation of such concerns require the assessment of the resonant frequencies of the aeroservoelastic system, which can be performed only by characterizing the dynamic stiffness of the actuator. This article reports the experimental activities carried out for the characterization of the stiffness response of a fault-tolerant fly-by-wire actuator for the primary flight controls of a modern jet trainer, starting from the feasibility studies of the experiments up to the execution of the vibration tests. The actuator stiffness performance is evaluated in different fail-operative modes by artificially injecting hydraulic and electrical failures, and the experimental data are interpreted by means of an LTI model of the flight actuator, highlighting and discussing the effects that the failures induce on the stiffness performance.

Parameters Optimization and Experimental Analysis in High Speed Machining

2012 ◽  
Vol 591-593 ◽  
pp. 480-483
Author(s):  
Huan Lin ◽  
Dong Qiang Gao ◽  
Zhong Yan Li ◽  
Jiang Miao Yi
Keyword(s):  
Genetic Algorithm ◽  
High Speed ◽  
Production Efficiency ◽  
Cutting Parameters ◽  
Processing Parameters ◽  
Parameters Optimization ◽  
High Speed Machining ◽  
Before And After ◽  
Processing Parameters Optimization ◽  
Cutting Parameters Optimization

First of all, in the cutting parameters optimization, according to the different processing conditions, optimization variables selection is different, including production efficiency the objective function and the constraint conditions of the machine tool. And then using genetic algorithm to build a high-speed processing parameters optimization model. The mathematical model explores the best solution through the software Matlab, and gets the optimal combination between the parameters of each cutting; high speed machining cutting parameters provides the reference for the choice of the user. Through the optimization of the comparison of the before and after that, using genetic algorithm cutting parameters optimization, mach inability got obvious improvement, in order to ensure the quality of processing also achieve the maximization of the production efficiency.

scholarly journals Impact of Cutting Forces and Chip Microstructure in High Speed Machining of Carbon Fiber – Epoxy Composite Tube

2017 ◽  
Vol 62 (3) ◽  
pp. 1771-1777 ◽  
Author(s):  
Y. Allwin Roy ◽  
K. Gobivel ◽  
K.S. Vijay Sekar ◽  
S. Suresh Kumar
Keyword(s):  
Carbon Fiber ◽  
Feed Rate ◽  
Cutting Forces ◽  
High Speed ◽  
Cutting Speed ◽  
Weight Ratio ◽  
Cutting Parameters ◽  
High Speed Machining ◽  
The Impact ◽  
Thrust Forces

AbstractCarbon fiber reinforced polymeric (CFRP) composite materials are widely used in aerospace, automobile and biomedical industries due to their high strength to weight ratio, corrosion resistance and durability. High speed machining (HSM) of CFRP material is needed to study the impact of cutting parameters on cutting forces and chip microstructure which offer vital inputs to the machinability and deformation characteristics of the material. In this work, the orthogonal machining of CFRP was conducted by varying the cutting parameters such as cutting speed and feed rate at high cutting speed/feed rate ranges up to 346 m/min/ 0.446 mm/rev. The impact of the cutting parameters on cutting forces (principal cutting, feed and thrust forces) and chip microstructure were analyzed. A significant impact on thrust forces and chip segmentation pattern was seen at higher feed rates and low cutting speeds.

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