Search results

In order to present a significant usage of the computer-aided design (CAD)/computer-aided manufacturing (CAM) systems in the apparel and textile industry, the current literature has been observed. Although the CAD/CAM systems have also been increasingly applied to all fields apparel and textile manufacturing for the last few decades, improving the precision, productivity and the organization of the information flow, they have not been fully utilized in these industrial fields. The paper aims to discuss these issues.

The paper is structured in three main sections showing the vast applicability of the CAD/CAM systems, the benefits provided by them and the future trend in their development.

Although the initial development of the CAD/CAM systems strived to completely eliminate manual and time-consuming operations, they have not been accepted in practice due to their inflexibility at making changes and the time needed for regenerating a complex parametric model. The textile and apparel industries show slow progress in acquiring the CAD/CAM systems.

This CAD/CAM technology enabled the customization in the design process according to individual needs and directed the textile and the apparel industry to moving into new directions such as the mass customization to personalization. The paper makes clear that although this technological concept is rather old, the use of the CAD/CAM systems will inevitably broaden in terms of applicability to new production stages.

The 4D CAD model has been accepted for better conceptualizing and comprehending the sequences and spatial constraints in a construction schedule. The purpose of this paper is to identify the deficiencies of the visualization of the 4D CAD model and to propose improvements.

The presentation abilities of the existing 4D CAD model are analyzed and compared with the other conventional methods, namely Gantt chart, network diagram, and the calendar. Four aspects of the visualization are addressed, namely the overview of a schedule, the duration of an activity, the relationship of an activity, and the project progress tracking. The proposed improvements employed different visual properties of 3D CAD objects such as color, line weight, and line type to represent the different activities' performing statuses. A prototype of the 4D CAD model with enhanced visualization was developed on a construction project case.

The model evaluation showed that this development could enhance the visualization of the 4D CAD model and provide a more informative construction schedule.

It is anticipated that the 4D CAD model with these enhancements can substitute for conventional presentation methods of construction schedules.

The purpose of this paper is to suggest the application of the line‐of‐balance (LoB) scheduling technique in combination with a 4D CAD workspace model as a method to improve the management of the flow of resources through locations in construction projects, defined as work flow. Current scheduling methods fail to consistently manage work flow, which can disrupt the construction process, leading to waste such as conflicts in time and space by construction crews.

LoB and 4D CAD are applied to a case study of multi‐story timber housing project involving the construction of 95 apartments in five six‐storey buildings. Based on the case study results, the benefits and limitations of the combined use of both methods are discussed.

The majority of the problems experienced during the actual construction process quickly become evident from an analysis of a relatively simple LoB diagram. Furthermore, the 4D CAD workspace model provides additional insights in the scheduling of construction activities, such as workspace availability, the spatial context of workspaces and partial overlap of workspaces.

Virtual design and construction methods based on principles from lean construction can contribute significantly to the value of the product and the elimination of waste in any construction project.

The paper refers to the guiding principles from lean construction in relation to virtual design and construction methods, such as simulations with 4D CAD. Additional research and studies of practical applications are suggested to facilitate the combination of principles from lean construction with virtual design and construction methods.

The purpose of this paper is to present the use of a CAD system for the analysis of meshing of spiral bevel gears.

The TCA computer programs are based on a purely mathematical model and require to get the numerical solution of a set of nonlinear equations. There are situations that the programs fail to obtain the proper solution. In such cases, geometrical gear models defined in CAD environment prove to be a good choice. This paper describes a tool for analyzing tooth contact and transmission errors of spiral bevel gear sets with tooth flanks represented as CAD free-form surfaces.

A new method has been proposed to keep those surfaces in continuous contact in the whole range of meshing of a mating tooth pair. During meshing, the points of contact as well as the corresponding angles of rotation of both the pinion and the ring gear are recorded. Thus, the tooth contact path as well as the motion transmission error graph is determined. Then, the contact pattern that is formed by a set of instantaneous contact ellipses is designated.

The TCA results are essential for the assessment of the gear set quality in the early stages of the process of its development.

All the results presented in graphical form are very illustrative and easy to interpret.

Suppliers of industrial paint finishing lines usually have only a relatively short time in which to submit tenders for the lines and get them up and running. “Simultaneous engineering” meets this need. Focuses on simulation software which allows the behaviour of projected installations as well as the associated physical and logistical processes to be examined in detail. Describes the 3D simulation system currently being used by ABB to determine object motion and material flow.

This paper is mainly concerned with the digital manufacturing technologies in the context of the shipbuilding industry. New concepts such as digital shipbuilding, virtual shipyard, and simulation‐based design (SBD) will be explored. After reviewing the digital shipbuilding, a case study will be presented using the virtual assembly simulation system for shipbuilding (VASSS), a simulation based tool, to evaluate block erection sequence taking account of shipyard facilities, operational efficiency and equipment replacement time.

This review paper aims to provide an overview of applications of direct rapid manufacturing assisted mold with conformal cooling channels (CCCs) and shows the potential of this technique in different manufacturing processes.

Key publications from the past two decades have been reviewed.

This study concludes that direct rapid manufacturing technique plays a dominant role in the manufacturing of mold with complicated CCC structure which helps to improve the quality of final part and productivity. The outcome based on literature review and case study strongly suggested that in the near future direct rapid manufacturing method might become standard procedure in various manufacturing processes for fabrication of complex CCCs in the mold.

Advanced techniques such as computer-aided design, computer-aided engineering simulation and direct rapid manufacturing made it possible to easily fabricate the effective CCC in the mold in various manufacturing processes.

This paper is beneficial to study the direct rapid manufacturing technique for development of the mold with CCC and its applications in different manufacturing processes.

Presents general properties and examples of weaves for two‐component multilayered woven fabrics. Such fabrics have a combination of properties which it is difficult to achieve in traditional fabrics (bulk combined with good tenacity, high cover level with porosity), can be used in liningless garments and can cope with ergonomical restrictions when using fibres with special protective properties. Describes a CAD system which can be used as an aid for a technologist to choose yarns for warp and weft, fabric weave and picks/ends count to meet demands specified by a particular fabric usage. It employs a new method of coding of multilayered fabric structure; mathematical methods used are based on the mechanical model of yarns interaction in a fabric. This describes the spatial disposition of yarns which allows production of any desired images of fabric geometry, i.e. surface smoothness or shape of pores. Discusses the complex nature of porosity of multilayered fabrics.

The growing complexity and pace of industrial technological change are forcing firms to forge new alliances and to respond more efficiently to market changes. This process is leading some companies towards more strategically directed integration within external agencies. Some are also adopting a sophisticated electronic toolkit in their design and development activities. These leading edge innovators are beginning to take on elements of the fifth‐generation (5G) innovation process. Describes developments towards this process.