Effect of Adaptive Slicing on Surface Integrity in Additive Manufacturing

2014 ◽  
Author(s):  
S. Sikder ◽  
Ahmad Barari ◽  
H. A. Kishawy
Keyword(s):  
Additive Manufacturing ◽  
Surface Integrity ◽  
Slice Thickness ◽  
Cad Model ◽  
Surface Error ◽  
Adaptive Slicing ◽  
Actual Surface ◽  
Error Factor ◽  
The Cost ◽  
Adaptive Direct Slicing

In today’s Additive Manufacturing (AM), a part is typically manufactured using layer by layer addition of material from a Computer Aided Design (CAD) model. Traditionally the CAD model is transferred to RP system after exchanging to Stereo Lithography (STL) format which is triangulated tessellation of the CAD model. Then it is sliced using different slice algorithms and machine constraints. The inherent uncertainties in this process have led to development of adaptive direct slicing technique. There are several adaptive slicing techniques but only few researches have been done to calculate an actual surface error factor and the cost aspect of the slicing algorithm. This paper proposes new adaptive algorithm to compute a surface error factor and to find the cost effective approach for slicing. The adaptive slicing algorithm dynamically calculates slice thickness and it is based on the allowable threshold for surface integrity error to optimize the cost and time. The paper also provides comparative study of previously developed adaptive models by the authors based on cusp height and surface integrity.

Surface Topography of Additive Manufacturing Parts Using a Finite Difference Approach

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Saeed Jamiolahmadi ◽  
Ahmad Barari
Keyword(s):  
Additive Manufacturing ◽  
Finite Difference ◽  
Surface Topography ◽  
Surface Integrity ◽  
Actual Surface ◽  
Texture Modeling ◽  
Data Points ◽  
Reconstructed Surface ◽  
Integrity Analysis ◽  
Finite Difference Approach

Inspection of surface integrity in additive manufacturing (AM) parts essentially needs a detailed understanding of their actual surface topography. Today's optical surface topography and roughness measurement sensors only provide information of the discrete points measured from the manufactured surface and not a detailed reconstruction of the surface topography. This paper presents a finite difference approach for reconstruction of the surface topography using sample measured data points. The developed methodology can be used in the surface quality inspection of the additive manufactured parts, their surface texture modeling, surface integrity analysis, and in planning for the required postprocessing or down-stream surface finish processes suitable for them. The methodology is fully implemented, and variety of experiments is conducted. The results show that the developed methodology is successful to reconstructed surface topography of the AM parts.

Increasing Part Accuracy in Additive Manufacturing Processes Using a k-d Tree Based Clustered Adaptive Layering

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Neeraj Panhalkar ◽  
Ratnadeep Paul ◽  
Sam Anand
Keyword(s):  
Additive Manufacturing ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Layer By Layer ◽  
Adaptive Slicing ◽  
Stl File ◽  
Build Time ◽  
Standard File Format ◽  
Aided Design ◽  
Profile Errors

Additive manufacturing (AM) is widely used in aerospace, automobile, and medical industries for building highly accurate parts using a layer by layer approach. The stereolithography (STL) file is the standard file format used in AM machines and approximates the three-dimensional (3D) model of parts using planar triangles. However, as the STL file is an approximation of the actual computer aided design (CAD) surface, the geometric errors in the final manufactured parts are pronounced, particularly in those parts with highly curved surfaces. If the part is built with the minimum uniform layer thickness allowed by the AM machine, the manufactured part will typically have the best quality, but this will also result in a considerable increase in build time. Therefore, as a compromise, the part can be built with variable layer thicknesses, i.e., using an adaptive layering technique, which will reduce the part build time while still reducing the part errors and satisfying the geometric tolerance callouts on the part. This paper describes a new approach of determining the variable slices using a 3D k-d tree method. The paper validates the proposed k-d tree based adaptive layering approach for three test parts and documents the results by comparing the volumetric, cylindricity, sphericity, and profile errors obtained from this approach with those obtained using a uniform slicing method. Since current AM machines are incapable of handling adaptive slicing approach directly, a “pseudo” grouped adaptive layering approach is also proposed here. This “clustered slicing” technique will enable the fabrication of a part in bands of varying slice thicknesses with each band having clusters of uniform slice thicknesses. The proposed k-d tree based adaptive slicing approach along with clustered slicing has been validated with simulations of the test parts of different shapes.

Additive Manufacturing on Building Construction

2021 ◽  
Vol 412 ◽  
pp. 207-216
Author(s):  
A.S. Guimarães ◽  
J.M.P.Q. Delgado ◽  
S.S. Lucas
Keyword(s):  
Additive Manufacturing ◽  
Building Construction ◽  
The Future ◽  
The Cost ◽  
Cost Of Construction

The future of construction will be directly connected with additive manufacturing (AM). It is easy to see the lack of consistency between jobs, labour inefficiency, schedule delays, delays on material delivery, exceeding budget projections and high percentage of material waste. Over the years, additive manufacturing has been a constant topic of discussion, in order to understand the limitations, applications and the overall impact on the cost of construction. In this work it is intended to present/discuss opportunities and challenges and the potential of AM to revolutionize the industry.

Representation of Burr Information in CAD Models

1999 ◽  
Author(s):  
Uma Jayaram ◽  
David Cramer ◽  
Narayanan Mathrubutham
Keyword(s):  
Manufacturing Processes ◽  
Cad Model ◽  
Size Information ◽  
Cad Models ◽  
Master Model ◽  
Physical Part ◽  
The Cost ◽  
Program Interface

Abstract Burr removal and deburring can often account for as much as one-third the cost of producing a part. Much attention is being focussed on integrating the deburring process into the product and manufacturing processes. Consequently there is a need for a system which can represent burr information in the CAD model as part of the product “master” model. In this paper, we present a method to capture burr information from the physical part and integrate that information with the CAD model of the part. Burr location and size information were recorded for the physical part. Methods were developed to encapsulate this information automatically in the CAD model through the applications program interface. This information was used to automatically create NC operations and sequences for downstream deburring.

Laser Additive Manufacturing

3D Printing ◽  
2017 ◽  
pp. 154-171 ◽  
Author(s):  
Rasheedat M. Mahamood ◽  
Esther T. Akinlabi
Keyword(s):  
Additive Manufacturing ◽  
Manufacturing Process ◽  
Computer Aided Design ◽  
Selective Laser Sintering ◽  
Three Dimensional ◽  
Cad Model ◽  
Laser Additive Manufacturing ◽  
Computer Aided ◽  
Manufacturing Technologies ◽  
Aided Design

Laser additive manufacturing is an advanced manufacturing process for making prototypes as well as functional parts directly from the three dimensional (3D) Computer-Aided Design (CAD) model of the part and the parts are built up adding materials layer after layer, until the part is competed. Of all the additive manufacturing process, laser additive manufacturing is more favoured because of the advantages that laser offers. Laser is characterized by collimated linear beam that can be accurately controlled. This chapter brings to light, the various laser additive manufacturing technologies such as: - selective laser sintering and melting, stereolithography and laser metal deposition. Each of these laser additive manufacturing technologies are described with their merits and demerits as well as their areas of applications. Properties of some of the parts produced through these processes are also reviewed in this chapter.

A Reverse Compensation Framework for Shape Deformation in Additive Manufacturing

2016 ◽  
Author(s):  
Kai Xu ◽  
Tsz-Ho Kwok ◽  
Yong Chen
Keyword(s):  
Additive Manufacturing ◽  
Computer Aided Design ◽  
Shape Deformation ◽  
Cad Model ◽  
Complex Deformation ◽  
Physical Measurements ◽  
Building Process ◽  
Aided Design ◽  
Thermal Cooling ◽  
And Control

Shape deformation is an important issue in additive manufacturing (AM) processes such as the projection-based Stereolithography. Volumetric shrinkage and thermal cooling during the photopolymerization process combined with other factors such as the layer-constrained building process lead to complex deformation that is difficult to predict and control. In this paper, a general reverse compensation method and related computation framework are presented to reduce the shape deformation of AM fabricated parts. During the reverse compensation process, the shape deformation is calculated based on physical measurements of shape deformation. A novel method for identifying the correspondence between the deformed shape and the given nominal computer-aided design (CAD) model is presented based on added markers. Accordingly, a new CAD model based on the shape deformation and related compensation is computed. The intelligently revised CAD model by going through the same building process can result in a fabricated part that is close to the nominal CAD model. Two test cases have been designed to demonstrate the effectiveness of the presented method and the related computation framework. The shape deformation in terms of L2- and L∞-norm based on measuring the geometric errors is reduced by 40–60%.

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