Hybrid methodologies of 3D beams reverse geometry analysis with embedded quality tools within the boundaries of a modern computer-aided design system

Modern CAD systems are essential in all phases of designing, evaluating and manufacturing mechanical parts. Efficient integration of CAE tools into modern CAD environments results in highly accurate procedures within a short time frame. In this work, a comparative study is presented, based on two novel hybrid methodologies for evaluating and optimising the reconstruction procedure for a 3D beam with an arbitrary cross-section. Both methodologies combine adaptive meshing techniques with quality tools (Taguchi method and response surface methodology), within the boundaries of a modern CAD system for the formation of the boundary element method (BEM) mathematical model. The application of such a methodology as an integrated CAD/CAE tool offers students and inexperienced engineers an excellent overview on the behaviour of structures in various loading and boundary conditions

Precision sculptured surface CNC machining using cutter location data

Industrial parts with sculptured surfaces are typically, manufactured with the use of CNC machining technology and CAM software to generate surface tool paths. To assess tool paths computed for 3-and 5-axis machining, the machining error is evaluated in advance referring to the parameter controlling the linearization of high-order curves, as well as the scallop yielded as a function of radial cutting engagement parameter. The two parameters responsible for the machining error are modeled and corresponding cutter location data for tool paths are utilized to compare actual trajectories with theoretical curves on a sculptured surface assessing thus the deviation when virtual tools are employed to maintain low cost; whilst ensuring high precision cutting. This operation is supported by applying a flexible automation code capable of computing the tool path; extracting its CL data; importing them to the CAD part and finally projecting them onto the part’s surface. For a given tolerance, heights from projected instances are computed for tool paths created by changing the parameters under a cutting strategy, towards the identification of the optimum tool path. To represent a global solution rough machining is also discussed prior to finish machining where the new proposals are mainly applied.</jats:p

Mechanical Biological Treatment Facility: Energy Recovery Assessment

Mechanical biological treatment (MBT) technology has been identified as the most preferred waste treatment technology that can effectively recover recyclable materials and high calorific value refuse-derived fuel (RDF) from municipal solid waste (MSW), as well as a viable alternative that can complement separate and source separation logistics in a waste management chain of developing countries with low budget for municipal solid waste management. Even though energy can be recovered or saved from utilisation of the output products of MBT plant, the operation of MBT plant consumes significant amount of energy, which prompted the need for further research of its energy sustainability performance potential. This chapter presents a framework for modelling of MBT plant as a combination of multi-stage mechanical separation processes for recovery of refuse derived fuel (RDF) and biological degradation process for stabilisation of municipal solid waste organic volatile components before disposal in landfill using a case study in Nigeria. The framework is a useful tool that can be used by policy-makers to support decision-making processes with respect to adoption and integration of MBT plant in local waste management system. It can also be used by technology developers for dimensioning a typical MBT plant configuration based on expected waste input quantities received at the plant and the framework will calculate and return quantities as well as the characteristics for products generated from the MBT plant

Development of a software-automated intelligent sculptured surface machining optimization environment

To ensure the quality of machined products at minimum cost and maximum effectiveness, it is crucial that selection of optimum machining parameters should be done when computer numerically controlled (CNC) machine tools technology is employed. Traditionally, experience of the operator plays a major role in the selection of efficient parameter values; however, attaining optimum ones each time by even skilled end users, is extremely difficult. This paper takes advantage of the possibilities of current computer-aided design (CAD)/computer-aided manufacturing (CAM) technology and implements a genetic algorithm for optimising CNC machining operations mainly for sculptured surfaces. The algorithm has been developed as a hosted application to a cutting-edge CAD/CAM system. Collaboration among applications has been achieved through programming for software automation by utilising the application programme interface of the system. The approach was implemented to a group of test sculptured models with different properties whilst one of them has been actually machined using typical resources. Results obtained after the implementation indicated that the methodology is capable of providing optimum values for process parameters on its way to maintain both productivity and high quality

Surface finish improvement of additive manufactured metal parts

Unlike materials subtractive technologies, Additive Manufacturing (AM) works on producing near net shape components according to a specific design at which the synthesis is achieved layer by layer. Additive manufacturing allows design freedom, making design-driven manufacturing a reality. However, its poor surface quality is considered as one of the key challenges that are worth to overcome. The main objective of this chapter is to report a comprehensive overview of the techniques used to improve the surface finish and their advancements of products made by metal Additive Manufacturing (AM) technologies and to highlight experimental processes and data. Powder bed fusion (PBF) and direct laser deposition (DLD) are the main processes covered in this review. The chapter starts with the literature review and introduction to the main metal AM processes and their surface roughness limitations, the effect of their parameters and the effect of the laser re-melting on the surface quality. Which then followed by details on the post-processing surface finish techniques such as laser polishing, chemical, and electro polishing. Experimental results of post surface finishing of AM parts by micro electrical discharge machining are also presented

Quality research on the performance of a virus-evolutionary genetic algorithm for optimized sculptured surface CNC machining, through standard benchmarks

This paper presents experimental results on a benchmark functions set, used for performance evaluation of Heuristics. Computational quality and robustness of a Virus-Evolutionary Genetic Algorithm developed to optimize manufacturing applications is assessed by conducting experiments and adjusting its intelligent operators so that its general computational behaviour is tuned up. Parameters considered include the generation number, population size, and virus infection operators