Papers by Keyword: Quality Control

Abstract: The buckling-restrained brace must be able to provide the designed structural performance in actual use. In other words, the buckling-restrained brace must retain its initial quality in during the fabricating process. In this study, for the purpose of ensuring the initial quality of the buckling-restrained brace using steel mortar planks (BRBSM), quality control values at the time of fabrication are set and conduct verification testing on clearance and gap.

Abstract: The microstructure of industrial leaded brass blanks made of leaded brass was examined for quality control. The exogenous inclusions and pores in the microstructure of the blanks were found. The microstructure was examined by means of traditional metallographic analysis methods. Is showed the transition from exogenous inclusions and pores, which were not removed in the initial processing stage, to the crack, which leads to billet destruction on one of the last processing stages. An algorithm for calculating the additional pressure that occurs when the mechanical action on the metal having a exogenous inclusions is suggested. Therefore, without the quality control leaded brass blanks a metallographic method, it is impossible to guarantee the reliable operation of machines and responsible purpose constructions.

Abstract: In recent years, as a new type of asphalt mixture, rubber asphalt mixture has a lot of excellent road performance, and is being widely used, but the rubber asphalt quality control measures are still in the exploratory stage. How to control the quality of rubber asphalt pavement, and provide technical support for more and more rubber asphalt pavement construction is particularly important. This article mainly analyzes and summarizes from raw material selection of rubber asphalt mixture, mix proportion design of rubber asphalt mixture and measures of construction quality control, forming a set of construction quality control technology of rubber asphalt pavement

Abstract: One of the main shortcomings of individualized training in the use of computer aided design (CAD), and computer aided manufacturing (CAM) tools is that students lack a sound and broad understanding of the type of tools, and their specific and integrated applications in industrial manufacturing. This study aimed to design an integrated curricular training programme in computer aided tools for the design and manufacture of mechanical components based on reverse engineering techniques. By using real products that students can see and touch, a scanned copy is obtained for subsequent reconstruction into a virtual three-dimensional model using the software for optimizing the point cloud, meshing, and creating both the surface and solid. Once the virtual three-dimensional model has been obtained, it is exported to a solid modelling CAD (3D-CAD) software for modification according to the geometrical requirements. The next step is for students to manufacture a component using rapid prototyping techniques, which allow them to visualize, analyse, and inspect a component to optimize its design. The use of computer aided manufacturing software enables students to design and plan machining operations virtually to obtain a computer numeric control (CNC) program for the manufacture of a component with a CNC machine tool. Finally, students perform a quality control of the component by employing a range of measurement techniques. This training program is integrated into the subjects of the mechanical engineering degree, where students can work with these tools in line with an intergraded curriculum.

Abstract: The manufacturing of polymer optical parts is a technologically complicated process because of a high precision of optical surfaces. Every responsible part has to be checked for homogeneity due to its high effect on optical properties. Thus, the creation of an area for automatized part control after injection molding is a pertinent goal. The study has applied the concept “Industry 4.0” to create a model of automatized area for polymer lens control. A photoelasticity control method for photosensitive materials was chosen.

Abstract: . In this study, characteristics of glass fiber reinforced recycled-PET composites by using direct fiber feeding injection molding (DFFIM) process were studied. The results, when varied processing conditions, indicated that decreasing of matrix feeding screw speed and increasing of number of glass fiber led to the increasing of fiber loading content, respectively. The average fiber length of glass fiber tended to decrease with the increasing of fiber loading content. Tensile modulus and tensile strength exhibited almost linear correlation with glass fiber load content. For study on stability of DFFIM process performance, at earliest stage of DFFIM process, discarding of at least five injected shots must be done in order to prepare the system availability of DFFIM process. The DFFIM machine could uninterruptedly manufacture composites without any problems occurred during 7 hours, which consequently provided high stability of product quality with long-term fabrication.

Abstract: Thermoplastic polymer matrix composites with continuous carbon fibre reinforcements are of crucial relevance in automotive industry. The mix of high performance and cost effective manufacturing makes them attractive for high volume production. However, it could be shown that production integrated end of line quality control is of strong importance to ensure continuous and traceable part quality. Besides, typical non destructive testing method specifications, higher production volumes additionally require short testing times. Herein, the application of active thermography as end of line quality control in composite production is evaluated and compared with results obtained by X-ray radiometry. It could be revealed that transient pulse phase thermography is a powerful tool to analyse part quality of continuous thermoplastic polymer matrix composites in short testing times.

Abstract: The durability of concrete structures in severe environments is not only related to design and materials but also to construction. Thus, much of the observed durability problems can be ascribed due to lack of proper quality control and quality assurance during concrete construction resulting in poorly achieved construction quality. Upon completion of new concrete structures, the achieved construction quality typically shows a high scatter and variability, and during operation of the structures, any weaknesses and deficiencies will soon be revealed whatever durability specifications and materials have been applied. To a certain extent, a probability approach to the durability design can accommodate the high scatter and variability. However, a numerical approach alone is insufficient for ensuring the durability; greater control and improvements in durability also require the specification of performance-based durability requirements which can be verified and controlled during concrete construction in order to achieve quality assurance. For new major concrete infrastructure, documentation of achieved construction quality and compliance to the durability specification should be essential parts of any rational approach to controlling and increasing the durability. In the present paper, a case study is presented which provides comparisons of work performed under performance and prescriptive durability specifications.

Abstract: The article covers an intelligent technology-based functional materials quality control process. It justifies the need for computer pattern recognition methods application in fabric analysis based on specimen digital photos taken in the course of quality control sampling. A two-level phase structure classification algorithm, that allows recognition of classes by teaching on a predefined known structures template array, is suggested. A working example is made of an algorithm application in the analysis of phase distribution on a photo of a hardened steel microsection with prescribed strength properties.

Abstract: In the context of an increased globalisation of sales and procurement markets companies are distributing their manufacturing activities in global networks. A key challenge is to ensure the overall production quality despite distributed value creation processes in complex manufacturing networks. Hence, a simulation model is presented, which allows for an evaluation of quality control strategies in global manufacturing networks. Based on the approach of Value Stream Mapping (VSM), which is enhanced by quality-relevant elements, a simulation approach is developed to dynamically evaluate different quality control strategies taking the individual target systems and site roles of the involved partners in the manufacturing network into account.