Toolpath Optimization for 3-Axis Milling of Thin-Wall Components

2020 ◽  
pp. 27-42
Author(s):  
Niccolò Grossi ◽  
Lorenzo Morelli ◽  
Antonio Scippa
Keyword(s):  
Thin Wall ◽  
Toolpath Optimization ◽  
Wall Components

Effect of the Thickness on Re-Characterisation of Subsurface to Surface Flaw: Application on Piping and Vessels

2016 ◽  
Author(s):  
Valéry Lacroix ◽  
Genshichiro Katsumata ◽  
Yinsheng Li ◽  
Kunio Hasegawa
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Surface Flaw ◽  
Thick Wall ◽  
Thin Wall ◽  
Rule Based ◽  
Asme Code ◽  
Crack Growth Rates ◽  
Wall Components

If a subsurface flaw is located near a component surface, the subsurface flaw is transformed to a surface flaw in accordance with a subsurface-to-surface flaw proximity rule. The re-characterization process from subsurface to surface flaw is adopted in all fitness-for-service (FFS) codes in different countries. However, the specific criteria of the recharacterizations are different among the FFS codes. The authors have proposed a new subsurface-to-surface flaw proximity rule based on experimental data and equivalent fatigue crack growth rates. Recently, the authors have highlighted through numerous fatigue crack growth calculations that, on one hand, the proximity rule provided in the current ASME Boiler and Pressure Vessel Code Section XI (ASME Code Section XI) can provide non conservative fatigue lives for thin wall components like pipes and, on the other hand, for thick wall components like vessels, the current proximity rule and the proposed one provide relatively similar fatigue lives. It appears therefore that the flaw-to-surface factor should be updated according to the thickness of the component or according to the type of component i.e. pipe or vessel. In this study, fatigue crack growth calculations were carried out on additional flaw configurations in thick wall pipes and thin wall vessels in order define the best limit for the thickness-dependence of the fatigue lives. Finally, a new subsurface to surface proximity rule depending on the thickness of the component is proposed.

scholarly journals Fixture Optimization in Turning Thin-Wall Components

Machines ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 68
Author(s):  
Lisa Croppi ◽  
Niccolò Grossi ◽  
Antonio Scippa ◽  
Gianni Campatelli
Keyword(s):  
Finite Element ◽  
Cutting Forces ◽  
Thin Wall ◽  
Effective Solution ◽  
Static Deflection ◽  
Thin Walled ◽  
Unstable Vibration ◽  
Dimensional Errors ◽  
Wall Components

The turning of thin-walled components is a challenging process due to the flexibility of the parts. On one hand, static deflection due to the cutting forces causes geometrical and dimensional errors, while unstable vibration (i.e., chatter) could compromise surface quality. In this work, a method for fixturing optimization for thin-walled components in turning is proposed. Starting from workpiece geometry and toolpath, workpiece deflections and system dynamics are predicted by means of an efficient finite element modeling approach. By analyzing the different clamping configurations, a method to find the most effective solution to guarantee the required tolerances and stable cutting conditions is developed. The proposed method was tested as a case study, showing its application and achievable results.

A Study of Chatter Stability Domain in Different Phases of Milling Process of Thin-Wall Component

2013 ◽  
Vol 711 ◽  
pp. 137-142
Author(s):  
Wei Wei Liu ◽  
Yuan Yuan Cai ◽  
Feng Li ◽  
Xiao Yan Li ◽  
Xu Sheng Wan
Keyword(s):  
Dynamic Model ◽  
Resonance Region ◽  
Stability Domain ◽  
Milling Process ◽  
Machining Accuracy ◽  
Thin Wall ◽  
Chatter Stability ◽  
Aero Engine ◽  
Cutting Chatter ◽  
Wall Components

Aeronautical thin-wall components are widely used in Aero-Engine, and the machining stability of the thin-wall components is a difficulty issue. In this paper, a single freedom dynamic model is set up to describe the dynamics of thin-wall milling process, and the stability of the dynamic model is analyzed with the discretization method. Then the modal parameters are gained in the different milling phases and the resonance region of spindle speed is proposed. Optimize the milling parameters with the chatter stability domain at different milling phases. The result shows that the cutting chatter can be restrained if getting the spindle speedcutting depth parameters considering the superposition area of chatter stability domains and avoiding the resonance region in the different milling phases. At last, the method is applied in Aero-Engine thin-wall blade milling, the metal remove rate increases greatly and the machining accuracy is improved greatly.

scholarly journals ANALYSIS OF CONTACT LOADS CONCENTRATION IN PRESSURE COUPLINGS OF THIN-WALL COMPONENTS

2019 ◽  
Vol 22 (3) ◽  
pp. 79-91
Author(s):  
S. V. Shishkin
Keyword(s):  
Generalized Solution ◽  
Contact Load ◽  
Surface Finishing ◽  
Solution Stability ◽  
Thin Wall ◽  
Algebraic Equations ◽  
Concentration Coefficient ◽  
Rigid Plastic ◽  
Linear Algebraic Equations ◽  
Wall Components

A number of aviation assemblies are made as pressure couplings of thin-wall components, e.g., shafts and hubs, durability of which is related to fitting contact load concentrations under cyclic and dynamic loadings. This article discusses a numeric solution to the contact problem. The solution is introducing into the calculations a conventional boundary layer, any shift of which is equivalent to a roughness deformation of fitting surfaces. The mathematical model of a pressure coupling is founded on a division of deformations into general (axisymmetric bending of components) and local deformations (microroughness compression) that are determined independently. To simplify the solution, the dependence of the contact convergence of the surfaces on the pressure is subjected to linearization in the form of a model of a rigid plastic body with linear strengthening. Convergence values in section are only determined by the pressure and do not depend on the stress-and-strain behaviors of areas adjacent to the rough interfacial space. The Green’s functions method is used to find radial shifts of components, while the solution is expressed by the Fredholm integral equation. That is reduced to a finite system of linear algebraic equations when the contact is made discrete. This approach provides solution stability through strengthening of the main diagonal of the resolving system, while the evaluation accuracy of the concentration coefficient depends on the subinterval value. It has been found that any disclosure of a coupling beneath the faces of an enveloping body is practically impossible for that model. The comprehensive approach provides a generalized solution for orthotropic and stepwise shells, as well as for components with specific design features and various strengths of areas adjacent to fitting sites. Deviations of the shape of the contact surfaces from the straightness are taken into account by its respective pressure coupling function. The analysis of the findings suggests that the concentration coefficient value slumps as the contact compliance coefficient of the borderline layer increases. Any shape deviations of the fitting surfaces, including their coning and concavity, increase the contact load concentration, while their convexity causes a reverse effect. We recommend using strengthening treatment methods, e.g., application of regular micropattern in the shape of helical flute at a certain pitch while applying a constant or a variable force on the diamond indenter, or vibration smoothing in order to control the shaft surface finishing to improve the stressand-strain behavior of the seam and to impart an artificial barrel shape of a preset value to the shaft. These technologies compensate contact load concentrations, and, together with the strengthening factor, enhance the fatigue limit of such assemblies.

Effects of Heat Input on Morphology of Thin Wall Components Fabricated by Wire and Arc Additive Manufacturing

2020 ◽  
Author(s):  
Fengchun Jiang ◽  
Laibo Sun ◽  
Ruisheng Huang ◽  
Hui Jiang ◽  
Guangyong Bai ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Heat Input ◽  
Thin Wall ◽  
Wall Components

Ultrasound flaw inspection of welded joints in thin-wall components

1998 ◽  
Vol 12 (10) ◽  
pp. 825-827
Author(s):  
V T Pronyakin ◽  
N K Rybakov ◽  
Yu N Panchenko
Keyword(s):  
Welded Joints ◽  
Thin Wall ◽  
Wall Components

Influence of a locally variable mold temperature on injection molded thin-wall components

2018 ◽  
Vol 38 (5) ◽  
pp. 475-481 ◽  
Author(s):  
Christopher Fischer ◽  
Ariane Jungmeier ◽  
Guido Peters ◽  
Dietmar Drummer
Keyword(s):  
Injection Molding ◽  
Mold Temperature ◽  
Thin Wall ◽  
Cooling Conditions ◽  
Mechanical Component ◽  
First Results ◽  
Injection Molded ◽  
Wall Components

Abstract Regarding injection-molding of semi-crystalline thermoplastics, controlling mold temperature and, therefore, the polymer melt’s cooling conditions can significantly affect component properties. In this research, an innovative dynamically tempered mold technology with different temperature zones is investigated, which will allow the production of thin-wall components with locally different component properties. First results show that due to influencing inner component properties, significant differences in optical and mechanical component properties can be achieved.

Sign in / Sign up

Export Citation Format

Share Document