scholarly journals Restraint of tool path ripple based on surface error distribution and process parameters in deterministic finishing

2010 ◽  
Vol 18 (22) ◽  
pp. 22973 ◽  
Author(s):  
Hao Hu ◽  
Yifan Dai ◽  
Xiaoqiang Peng
Keyword(s):  
Process Parameters ◽  
Tool Path ◽  
Error Distribution ◽  
Surface Error

Development of Tool Path Correction Algorithm in Incremental Sheet Forming

2014 ◽  
Vol 622-623 ◽  
pp. 382-389 ◽  
Author(s):  
Antonio Fiorentino ◽  
G.C. Feriti ◽  
Elisabetta Ceretti ◽  
C . Giardini ◽  
C.M.G. Bort ◽  
...  
Keyword(s):  
Tool Path ◽  
Error Distribution ◽  
Sheet Forming ◽  
Incremental Sheet Forming ◽  
Correction Algorithm ◽  
Forming Process ◽  
Part Geometry ◽  
Toolpath Planning ◽  
The Difference ◽  
Tool Path Correction

The problem of obtaining sound parts by Incremental Sheet Forming is still a relevant issue, despite the numerous efforts spent in improving the toolpath planning of the deforming punch in order to compensate for the dimensional and geometrical part errors related to springback and punch movement. Usually, the toolpath generation strategy takes into account the variation of the toolpath itself for obtaining the desired final part with reduced geometrical errors. In the present paper, a correction algorithm is used to iteratively correct the part geometry on the basis of the measured parts and on the calculation of the error defined as the difference between the actual and the nominal part geometries. In practice, the part geometry is used to generate a first trial toolpath, and the form error distribution of the resulting part is used for modifying the nominal part geometry and, then, generating a new, improved toolpath. This procedure gets iterated until the error distribution becomes less than a specified value, corresponding to the desired part tolerance. The correction algorithm was implemented in software and used with the results of FEM simulations. In particular, with few iterations it was possible to reduce the geometrical error to less than 0.4 mm in the Incremental Sheet Forming process of an Al asymmetric part, with a resulting accuracy good enough for both prototyping and production processes.

Utilization of a Curly Toolpath in Friction Stir Welding

2021 ◽  
Vol 1165 ◽  
pp. 15-29
Author(s):  
Tyler J. Grimm ◽  
Derek Shaffer ◽  
Ihab Ragai
Keyword(s):  
Friction Stir Welding ◽  
Process Parameters ◽  
Tool Path ◽  
Base Material ◽  
The Other ◽  
Weld Strength ◽  
Mechanical Mixing ◽  
Material Interface ◽  
Friction Stir ◽  
High Level

Friction stir welding (FSW) is an advanced solid-state metal joining technique. This operation fuses adjacent materials through the use of a non-consumable, rotating tool, which is plunged into and travels along the seam of the materials. Since this joining method avoids the bulk melting of the base materials, it is considered a relatively energy efficient process. Additionally, the strength of the base material is often improved due to significant grain refinement resulting from the stirring action of the tool at relatively low temperatures. Another inherent benefit is that the joint thickness, which is dependent on the length of the pin, can be much greater than most other joining processes and can also be well controlled. This joining method conventionally relies on the friction at the tool-base material interface to stir materials. Other research has implemented complex tooling to mechanically enhance this stirring action. However, these tools are often expensive, requiring a high level of capability within industry. In order to improve the weld strength of FSW, a novel toolpath is utilized which significantly improves the mechanical mixing of the constituent materials without the need for complex tooling, such as tools with threaded pins. The path currently investigated forms a curl as it travels both perpendicular and parallel to the joint. This motion is used to extend the stirring action of the tool to regions outside the immediate joint area. It was found that this tool path is effective in improving weld strength under specific process parameters. Constraining the tool's axis normal to the workpiece surface resulted in a void that was formed in the majority of tests; however, this void was eliminated with modification of the process parameters. An uneven distribution of heat was recognized within this testing in which one side of the joint was hotter than the other. This observation may be used in future studies to perform multi-material joining where it is often necessary to increase the temperature of one material more than the other.

An Experimental and Numerical Study of Dieless Water Jet Incremental Microforming

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Yi Shi ◽  
Weizhao Zhang ◽  
Jian Cao ◽  
Kornel F. Ehmann
Keyword(s):  
Numerical Model ◽  
Sheet Metal ◽  
Process Parameters ◽  
High Speed ◽  
Tool Path ◽  
Numerical Study ◽  
Single Point ◽  
Thin Sheet ◽  
Water Jet ◽  
Truncated Cone

Conventional single-point incremental forming (SPIF) is already in use for small batch prototyping and fabrication of customized parts from thin sheet metal blanks by inducing plastic deformation with a rigid round-tip tool. The major advantages of the SPIF process are its high flexibility and die-free nature. In lieu of employing a rigid tool to incrementally form the sheet metal, a high-speed water jet as an alternative was proposed as the forming tool. Since there is no tool-workpiece contact in this process, unlike in the traditional SPIF process, no lubricant and rotational motion of the tool are required to reduce friction. However, the geometry of the part formed by water jet incremental microforming (WJIMF) will no longer be controlled by the motion of the rigid tool. On the contrary, process parameters such as water jet pressure, stage motion speed, water jet diameter, blank thickness, and tool path design will determine the final shape of the workpiece. This paper experimentally studies the influence of the above-mentioned key process parameters on the geometry of a truncated cone shape and on the corresponding surface quality. A numerical model is proposed to predict the shape of the truncated cone part after WJIMF with given input process parameters. The results prove that the formed part's geometric properties predicted by the numerical model are in excellent agreement with the actually measured ones. Arrays of miniature dots, channels, two-level truncated cones, and letters were also successfully fabricated on stainless-steel foils to demonstrate WJIMF capabilities.

Control of Thermal Effect in Ion Beam Figuring Process Based on Low-Pass Filtering

2011 ◽  
Vol 120 ◽  
pp. 360-365
Author(s):  
Zheng Yuan ◽  
Yi Fan Dai ◽  
Hao Yu ◽  
Xu Hui Xie ◽  
Lin Zhou
Keyword(s):  
Thermal Effect ◽  
Ion Beam ◽  
Error Distribution ◽  
Initial Surface ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Surface Error ◽  
Dwelling Time ◽  
Low Pass ◽  
Ion Beam Figuring

During ion beam figuring process, most heat energy is absorbed by optics surface, heating the workpiece surface un-uniformly, called thermal effect. Thermal effect leads to distortion even cracking of the optical figure due to high temperature and temperature gradients, especially for the temperature sensible materials such as BK7, KDP and CaF2. One of the methods on decreasing thermal effect is decreasing total dwelling time and dwelling time gradients. According to the ability of ion beam correction, It is proposed that a new surface error distribution is obtained by filtered by a low pass filter from the initial surface error distribution measured by interferometer, and then it is used to calculate the dwelling time function. It is indicated by simulation that this measured decreases the total dwelling time and dwelling time gradients, reduces the temperature peak and heat stress. At last, a flat surface with the surface accuracy of 0.002λ rms is obtained from the initial surface error of 0.006λ rms, proving that high precision surface can be achieved with the surface after low pass filtering. So it is of great signification for actual application on ion beam figure temperature sensible materials.

Minimax Optimization Strategy for Process Parameters Planning: Toward Interference-Free Between Tool and Flexible Workpiece in Milling Process

2016 ◽  
Vol 139 (5) ◽  
Author(s):  
Xiao-Ming Zhang ◽  
Dong Zhang ◽  
Le Cao ◽  
Tao Huang ◽  
Jürgen Leopold ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Process Parameters ◽  
Tool Path ◽  
Milling Process ◽  
Tool Path Generation ◽  
Path Generation ◽  
Thin Wall ◽  
Minimax Optimization ◽  
Envelope Surface ◽  
Flexible Workpiece

In milling of flexible workpieces, like axial-flow compressor impellers with thin-wall blades and deep channels, interference occurrence between workpiece and tool shaft is a great adverse issue. Even though interference avoidance plays a mandatory role in tool path generation stage, the generated tool path remains just a nominally interference-free one. This challenge is attributed to the fact that workpiece flexibility and dynamic response cannot be considered in tool path generation stage. This paper presents a strategy in process parameters planning stage, aiming to avoid the interference between tool shaft and flexible workpiece with dynamic response in milling process. The interference problem is formulated as that to evaluate the approaching extent of two surfaces, i.e., the vibrating workpiece and the swept envelope surface generated by the tool undergoing spatial motions. A metric is defined to evaluate quantitatively the approaching extent. Then, a minimax optimization model is developed, in which the optimization objective is to maximize the metric, so as the interference-free can be guaranteed while constraints require the milling process to be stable and process parameters to fall into preferred intervals in which material removal rate is satisfactory. Finish milling of impeller using a conical cutter governed by a nominally interference-free tool path is numerically simulated to illustrate the dynamics responses of the spatially distributed nodal points on the thin-wall blade and approaching extent of the time-varying vibrating blades to the tool swept envelope surface. Furthermore, the present model results suggest to use an optimal process parameters set in finish milling, as a result improving machining efficiency in addition to ensuring the interference-free requirement. The model results are verified against milling experiments.

scholarly journals A Novel Error Compensation Method of Five-axis Flank Milling of Ruled Surface by Modifying Tool Path

2021 ◽  
Author(s):  
Gaiyun He ◽  
Chenglin Yao ◽  
Yicun Sang ◽  
Yichen Yan
Keyword(s):  
Error Compensation ◽  
Tool Path ◽  
Error Distribution ◽  
Ruled Surface ◽  
Compensation Method ◽  
Distribution Model ◽  
Flank Milling ◽  
Average Error ◽  
Machining Accuracy ◽  
Five Axis

Abstract Five-axis flank milling is widely used in the aerospace and automotive industry. However, diverse sources of errors prevent the improvement of machining accuracy. This paper proposes a novel error compensation method for five-axis flank milling of ruled surface by modifying the original tool path according to the error distribution model. The method contains three steps: First, the errors at the middle of the straight generatrix on the machined surface are calculated according to error distribution, and the corresponding normal vectors are obtained by geometric calculation. Second, multi-peaks Gaussian fitting method is utilized to make connections between parameters in the original tool path and error distribution. Finally, the new tool path is generated by adjusting original tool path. Machining experiments are performed to test the effectiveness of the proposed error compensation method. The error distribution after compensation shows that the average error decreases 74%, and the maximum error (contains overcutting and undercutting) decreases 26%. Results show that the proposed error compensation method is effective to improve the accuracy for five-axis flank milling.

Configuration-Space Searching and Optimizing Tool Orientations for 5-Axis Machining

Manufacturing ◽  
2002 ◽  
Author(s):  
Cha-Soo Jun ◽  
Yuan-Shin Lee ◽  
Kyungduck Cha
Keyword(s):  
Configuration Space ◽  
High Performance ◽  
Tool Path ◽  
Sculptured Surface ◽  
Tool Orientation ◽  
Machined Surface ◽  
Surface Error ◽  
Surface Machining ◽  
Sculptured Surface Machining ◽  
Rear Gouging

This paper presents a methodology and algorithms of optimizing and smoothing the tool orientation control for 5-axis sculptured surface machining. A searching method in the machining configuration space (C-space) is proposed to find the optimal tool orientation by considering the local gouging, rear gouging and global tool collision in machining. Based on the machined surface error analysis, a boundary search method is developed first to find a set of feasible tool orientations in the C-space to eliminate gouging and collision. By using the minimum cusp height as the objective function, we first determine the locally optimal tool orientation in the C-space to minimize the machined surface error. Considering the adjacent part geometry and the alternative feasible tool orientations in the C-space, tool orientations are then globally optimized and smoothed to minimize the dramatic change of tool orientation during machining. The developed method can be used to automate the planning and programming of tool path generation for high performance 5-axis sculptured surface machining. Computer implementation and examples are also provided in the paper.

Predictive Surface Generation and Characterization for Cylindrical Turning Processes

2005 ◽  
Author(s):  
Yashpal Kovvur ◽  
Hemant Ramaswami ◽  
Sam Anand
Keyword(s):  
Process Parameters ◽  
Surface Characterization ◽  
Tool Path ◽  
Surface Generation ◽  
Generation Model ◽  
Machining Parameters ◽  
Machined Surface ◽  
Motion Error ◽  
Simulation Based ◽  
Manufacturing Errors

This paper presents a generalized simulation based approach for generation and characterization of turned surfaces based on process parameters and manufacturing errors. The presented model shows that with proper analytical modeling along with appropriate process monitoring system (force signals, vibration signals, spindle motion error signals etc.,) a comprehensive surface generation model can be developed. First, the tool nose geometry and cutting-force induced vibrations are superimposed to obtain the cutting tool path. Next, the information obtained from spindle motion errors is used to analytically formulate the position of each point on the machined surface. Regression models are fit to establish the relationship between form error / surface roughness and input parameters. The simulation-based approach presented here provides a quantitative bridge between process parameters/manufacturing errors and surface characterization metrics. Such a scheme would allow manufacturing engineers to pre-select processes, parameters, and capable machines to achieve design specification. This model will allow engineers to proactively control the influence of machining parameters on product quality through computer simulation, and, thus, “do things right the first time.”

Sign in / Sign up

Export Citation Format

Share Document