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Apparel pattern making is an age‐old occupation which is full of heuristics and unwritten rules. These rules have yet to be comprehensively studied for possible incorporation into apparel CAD systems. At present, most of these systems have drafting subsystems that address only a portion of this process. Explores pattern making in detail. Seeks to identify the motivations behind all its procedures and operations. A knowledge of such motivations provides a better understanding of the whole process. This knowledge can subsequently be used to design better computer‐aided pattern‐making systems.

Apparel pattern making creates a set of pattern pieces of fabric which are sewn into the desired garment. The pattern pieces are developed through fashion analysis, pattern design and pattern drafting. Seeks to build an object‐oriented model of the apparel pattern‐making process through these subprocesses. Defines the model in terms of a requirements specification and subsequently uses it in the development of a computerized pattern‐making system. Uses object behaviour analysis, which is derived from object‐oriented technology, as the method for defining the model.

To investigate the “staircase effect”, which is one of the most significant manifestations of part inaccuracy in liquid‐based rapid prototyping (RP) processes, on multi‐layer RP parts made using a thick layer deposition and photo‐curing process in a stepless rapid prototyping (SRP) system.

The building of a five‐layer part is simulated layer by layer using a finite element method based on an incremental elastic model, to analyze the staircase effect due to shrinkage induced by polymerization and temperature variation. The influence of various factors such as layer thickness and intensity of incident UV light is studied. The results were verified experimentally.

Results show that the staircase amount increases 20 percent and 300 percent with light intensity increasing from 65 to 145 mW/cm² and layer thickness increasing from 0.2 to 2.0 mm, respectively. It is also found that the overall staircase is below 100 μm, which suggests that the SRP process improves surface quality greatly compared to other RP systems, and can provide enough accuracy for fabricating functional parts.

The results apply only to the material used in the work: an acrylate‐based photopolymer resin, C123, produced by Tianjin Chemical Co., China. Also, the thickness of the layers is fixed at 6 mm.

Provides a method to analyze the origin and amount of the staircase effect, upon which to better control the surface finish of RP parts. New materials and different layer thicknesses can be investigated using the same method.

Apart from the above practical implication, this paper establishes the parameters that influence the shrinkage of the material used in SRP.

In additive manufacturing processes such as stereolithography and fused deposition modeling, optimal part orientation is pivotal in improving the quality of the part. This paper aims to propose an automatic and optimal part orientation system to improve part quality/accuracy in additive manufacturing, which minimizes the production time and hence reduces the cost of product.

The developed system reads STEP AP 203 E2 file from CATIA V5 and generates data extraction output file by extracting the relevant geometrical and topological data using an object-oriented approach. Afterwards, the algorithms and rules are developed to extract and recognize feature faces along with their geometric properties such as face type, face area, parallelism and perpendicularity. The feature data obtained that are used to develop feasible part orientations depend on the maximization of G&DT for all part faces. The automatic slicing is then achieved by creating slicing file using CATVBA editor inside CATIA V5.

After slicing, output data are exported in Excel data sheet to calculate the total additive volume of the part. The building time of the part is then calculated on the basis of machine parameters, part geometry, part height, layer thickness and amount of support volume needed to build the part. The optimal orientation of the part is achieved by maximization of G&DT value and minimization of production time. The proposed methodology is tested using an illustrative example.

Although lot of approaches have been discussed in the literature, automation of setup planning/orientation of the part in additive manufacturing is not fully attained. Therefore, the article focuses on the automation of setup planning by adding automatic feature extraction and recognition module along with the automatic slicing during setup planning. Moreover, the significance of adding feature extraction and recognition module is to achieve best accuracy for form feature faces and hence reduction in post processing machining/finishing operations.

The purpose of this work is to explain the emergence of warpage due to a locally and temporally inhomogeneous shrinkage in 3D printing (Binder-Jetting) of polymers.

An analysis of shrinkage yields parameters for a one-dimensional layer model of the binding process. Based on this, residual stresses and deformation are calculated by means of a numerical simulation model.

The simulation supports the assumption that the curling of specimens is created by a force transmission between layers due to inhomogeneous shrinkage. Furthermore, the layered production process might contribute to nonlinear deformations of not horizontally orientated surfaces.

The simulation allows imitating the warping during the manufacturing process qualitatively. Exact values of deformations cannot be predicted, yet.

The results expand the knowledge about warpage effects in 3D printing caused by the layer-wise building process.

The developed model imitates the mechanisms leading to deformations during the 3D printing process, focusing on the physical interaction of layers with each other.