Preliminary Design Analysis of RoPax for Nigeria Coastal Water Pliability

This paper describes procedures used for preliminary design analysis of a roll-on;roll-off passenger vessel abbreviated as RoPox. As the name presupposes, RoPax ships are used for carriage of rolling type-cargoes and as well as passengers. RoPax are usually medium size ships with high performance characteristics that enhance their application for both long and short distance journeys. For instance, in Nigeria where most of her regions are surrounded by seas, this type of ship is apt. Several methods were implemented in order to obtain some preliminary results scoped in dimension, hydrostatic and hydrodynamic characteristics. The methods used correlate well with conventional values discussed in reality and in literatures.

MECHANISM DESIGN AND MOTION ANALYSIS OF A SPHERICAL MOBILE ROBOT

A new spherical mobile robot BHQ-1 is designed. The spherical robot is driven by two internally mounted motors that induce the ball to move straight and turn around on a fiat surface. A dynamic model of the robot is developed with Lagrange method and factors affecting the driving torque of two motors are analyzed. The relationship between the turning radius of the robot and the length of two links is discussed in order to optimize its mechanism design. Simulation and experimental results demonstrate the good controllability and motion performance of BHQ-1.

A Framework for Web-Based Mechanical Design and Analysis

In this paper, a Web-based Mechanical Design and A na lysis Framework (WMDAF) is proposed. This WMADF allows designers to develop web -based computer aided programs in a systematic way during the collaborative mec hanical system design and analysis process. This system is based on an emerg ing web-based Content Management System (CMS) called eXtended Object Oriented P ortal System (XOOPS). Due to the Open Source Status of the XOOPS CMS, programs d eveloped with this framework can be further customized to satisfy the demands of the user. To introduce the use of this framework, this paper exams three differ ent types of mechanical design and analysis problems. First, a repetitive design consideration and calculation process is transferred into WMADF programs to gai n efficiency for wired collaborative team. Second, the considered product solid model is created directly through the use of XOOPS program and Microsoft Compone nt Object Model (COM) instances. To the end of the paper, an example linked with ANSYS is used to indicate the possible application of this framework.

Analysis and Design of Quality Management Platform for the Entire Process of Characteristic Software Talent Training

At the end of 2021 to create a new model of characteristic software talent training for independent and controllable key software fields,the Ministry of Education and the Ministry of Industry and Information Technology jointly approved the establishment of the first batch of 33 Characteristic Pilot Schools of software.As a member of characteristic software schools,the HIT School of Software has been approved and will focus on the construction of 2 characteristic directions,which are large-scale industrial software and industrial professional application software.In order to achieve the goal,it is urgent to develop a comprehensive management platform to control the entire process of talent training,so that we can standardize,modelling,and digitized the entire process of characteristic software talent training.By relating all aspects of student training with and implementing the ability-index mechanisms,we will continuously collect big-data of the entire process of student growth,and generate multidimensional student ability portraits for evaluating the effect of talent training,and adjust as well as optimizing the growth path for students themselves during their studying.Employers will be able to identify talents accurately and provide effective reference for colleges to adjust training plans.This paper will analyze the needs of the platform,provide demand analysis of the platform,extract the correlation model between training,conclude the relations between ability-index activities and ability indicators,and give a reasonable overall system design scheme.

CONSTRUCTION DESIGN AND FLOW ANALYSIS OF CENTRIFUGAL PUMP IMPELLER WITH SUPER-LOW SPECIFIC SPEED

Some commonly used constructions and their design principles of centrifugal pump impeller with super low specific speed are introduced. The internal flow related to pump performance is analysed primarily.

Simulation and Experimental Analysis of Vortex Tube Using Steel Material

Experimental and computational fluid dynamics (CFD) are investigated through the vortex tube system. The benefit of vortex tube is a counter flow type tube, which has further designed and fabricated for investigation. The whole set up is consisting of a simple device that can separate a single stream of compressed air into two streams;one is at high temperature and the other is lower temperature following an inlet gas stream. The advantages of this tube are their compactness, safety, and low equipment cost mainly used in cooling and heating applications. This study addressed three-dimensional flows;the domain is using computational fluid dynamics (CFD) method and experimental approach to optimize the direction of RHVT. Through the CFD analysis, the best cold end diameter (dc), number of nozzles, and the best parameters for obtaining the highest hot gas temperature and lowest cold gas temperature were obtained and verified by experimental procedures.

Performance-based seismic design of nonstructural building components:The next frontier of earthquake engineering

With the development and implementation of performance-based earthquake engineering,harmonization of performance levels between structural and nonstructural components becomes vital. Even if the structural components of a building achieve a continuous or immediate occupancy performance level after a seismic event,failure of architectural,mechanical or electrical components can lower the performance level of the entire building system. This reduction in performance caused by the vulnerability of nonstructural components has been observed during recent earthquakes worldwide. Moreover,nonstructural damage has limited the functionality of critical facilities,such as hospitals,following major seismic events. The investment in nonstructural components and building contents is far greater than that of structural components and framing. Therefore,it is not surprising that in many past earthquakes,losses from damage to nonstructural components have exceeded losses from structural damage. Furthermore,the failure of nonstructural components can become a safety hazard or can hamper the safe movement of occupants evacuating buildings,or of rescue workers entering buildings. In comparison to structural components and systems,there is relatively limited information on the seismic design of nonstructural components. Basic research work in this area has been sparse,and the available codes and guidelines are usually,for the most part,based on past experiences,engineering judgment and intuition,rather than on objective experimental and analytical results. Often,design engineers are forced to start almost from square one after each earthquake event: to observe what went wrong and to try to prevent repetitions. This is a consequence of the empirical nature of current seismic regulations and guidelines for nonstructural components. This review paper summarizes current knowledge on the seismic design and analysis of nonstructural building components,identifying major knowledge gaps that will need to be filled by future research. Furthermore,considering recent trends in earthquake engineering,the paper explores how performance-based seismic design might be conceived for nonstructural components,drawing on recent developments made in the field of seismic design and hinting at the specific considerations required for nonstructural components.

STRUCTURE PARAMETERS DESIGN AND PERFORMANCE TEST OF FUEL INJECTION SYSTEM

Based on the numerical simulation analysis, structure parameters of the high pressure fuel pump and common rail as well as flow limiter are designed and the GD-1 high pressure common rail fuel injection system is self-developed. Fuel injection characteristics experiment is performed on the GD-1 system. And double-factor variance analysis is applied to investigate the influence of the rail pressure and injection pulse width on the consistency of fuel injection quantity, thus to test whether the design of structure parameters is sound accordingly. The results of experiment and test show that rail pressure and injection pulse width as well as their mutual-effect have no influence on the injection quantity consistency, which proves that the structure parameters design is successful and performance of GD-1 system is sound.

DIRECT DIGITAL DESIGN AND SIMULATION OF MESHING IN WORM-GEAR DRIVE

A direct digital design method （DDDM） of worm-gear drive is proposed. It is directly based on the simulation of manufacturing process and completely different from the conventional modeling method. The loaded tooth contact analysis （LTCA） method is analyzed, in which the advanced surface to surface searching technique is included. The influence of misalignment errors and contact deformations on contact zone and transmission error （TE） is discussed. Combined modification approach on worm tooth surface is presented. By means of DDDM and LTCA, it is very conven- ient to verify the effect of worm-gear drive＇s modification approach. The analysis results show that, the modification in profile direction reduces the sensitivity of worm-gear drive to misalignment errors and the modification in longitudinal direction decreases the TE. Thus the optimization design of worm-gear drive can be achieved prior to the actual manufacturing process.

Robust Design Optimization Method for Centrifugal Impellers under Surface Roughness Uncertainties Due to Blade Fouling

Blade fouling has been proved to be a great threat to compressor performance in operating stage. The current researches on fouling-induced performance degradations of centrifugal compressors are based mainly on simplified roughness models without taking into account the realistic factors such as spatial non-uniformity and randomness of the fouling-induced surface roughness. Moreover, little attention has been paid to the robust design optimization of centrifugal compressor impellers with considerations of blade fouling. In this paper, a multi-objective robust design optimization method is developed for centrifugal impellers under surface roughness uncertainties due to blade fouling. A three-dimensional surface roughness map is proposed to describe the nonuniformity and randomness of realistic fouling accumulations on blades. To lower computational cost in robust design optimization, the support vector regression（SVR） metamodel is combined with the Monte Carlo simulation（MCS） method to conduct the uncertainty analysis of fouled impeller performance. The analyzed results show that the critical fouled region associated with impeller performance degradations lies at the leading edge of blade tip. The SVR metamodel has been proved to be an efficient and accurate means in the detection of impeller performance variations caused by roughness uncertainties. After design optimization, the robust optimal design is found to be more efficient and less sensitive to fouling uncertainties while maintaining good impeller performance in the clean condition. This research proposes a systematic design optimization method for centrifugal compressors with considerations of blade fouling, providing a practical guidance to the design of advanced centrifugal compressors.

MicroGrid Designer:user-friendly design,operation and control assist tools for resilient microgrid and autonomous community

During this decade,many countries have experienced natural and accidental disasters,such as typhoons,floods,earthquakes,and nuclear plant accidents,causing catastrophic damage to infrastructures.Since the end of 2019,all countries of the world are struggling with the COVID-19 and pursuing countermeasures,including inoculation of vaccine,and changes in our lifestyle and social structures.All these experiences have made the residents in the affected regions keenly aware of the need for new infrastructures that are resilient and autonomous,so that vital lifelines are secured during calamities.A paradigm shift has been taking place toward reorganizing the energy social service management in many countries,including Japan,by effective use of sustainable energy and new supply schemes.However,such new power sources and supply schemes would affect the power grid through intermittency of power output and the deterioration of power quality and service.Therefore,new social infrastructures and novel management systems to supply energy and social service will be required.In this paper,user-friendly design,operation and control assist tools for resilient microgrids and autonomous communities are proposed and applied to the standard microgrid to verify its effectiveness and performance.

Numerical analyses in the design of umbrella arch systems

Due to advances in numerical modelling, it is possible to capture complex support-ground interaction intwo dimensions and three dimensions for mechanical analysis of complex tunnel support systems,although such analysis may still be too complex for routine design calculations. One such system is theforepole element, installed within the umbrella arch temporary support system for tunnels, whichwarrants such support measures. A review of engineering literature illustrates that a lack of designstandards exists regarding the use of forepole elements. Therefore, when designing such support, designersmust employ complex numerical models combined with engineering judgement. With referenceto past developments by others and new investigations conducted by the authors on the Driskos tunnelin Greece and the Istanbul metro, this paper illustrates how advanced numerical modelling tools canfacilitate understanding of the influences of design parameters associated with the use of forepole elements.In addition, this paper highlights the complexity of the ground-support interaction whensimulated with two-dimensional （2D） finite element software using a homogenous reinforced region,and three-dimensional （3D） finite difference software using structural elements. This paper further illustratessequential optimisation of two design parameters （spacing and overlap） using numericalmodelling. With regard to capturing system behaviour in the region between forepoles for the purpose ofdimensioning spacing, this paper employs three distinctive advanced numerical models： particle codes,continuous finite element models with joint set and Voronoi blocks. Finally, to capture the behaviour/failure ahead of the tunnel face （overlap parameter）, 2D axisymmetric models are employed. Finally,conclusions of 2D and 3D numerical assessment on the Driskos tunnel are drawn. The data enriched casestudy is examined to determine an optimum design, based on the proposed optimisation of designparameters, of forepole elements related to the site-specific considerations. 2014 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.

Design Change Model for Effective Scheduling Change Propagation Paths

Changes in requirements may result in the increasing of product development project cost and lead time, therefore, it is important to understand how require- ment changes propagate in the design of complex product systems and be able to select best options to guide design. Currently, a most approach for design change is lack of take the multi-disciplinary coupling relationships and the number of parameters into account integrally. A new design change model is presented to systematically analyze and search change propagation paths. Firstly, a PDS-Be- havior-Structure-based design change model is established to describe requirement changes causing the design change propagation in behavior and structure domains. Secondly, a multi-disciplinary oriented behavior matrix is utilized to support change propagation analysis of complex product systems, and the interaction relationships of the matrix elements are used to obtain an initial set of change paths. Finally, a rough set-based propagation space reducing tool is developed to assist in narrowing change propagation paths by computing the importance of the design change parameters. The proposed new design change model and its associated tools have been demonstrated by the scheduling change propagation paths of high speed train＇s bogie to show its feasibility and effectiveness. This model is not only supportive to response quickly to diversified market requirements, but also helpful to satisfy customer require- ments and reduce product development lead time. The proposed new design change model can be applied in a wide range of engineering systems design with improved efficiency.

Real-time Design Constraints in Implementing Active Vibration Control Algorithms

Although computer architectures incorporate fast processing hardware resources, high performance real-time implementation of a complex control algorithm requires an efficient design and software coding of the algorithm so as to exploit special features of the hardware and avoid associated architecture shortcomings. This paper presents an investigation into the analysis and design mechanisms that will lead to reduction in the execution time in implementing real-time control algorithms. The proposed mechanisms are exemplified by means of one algorithm, which demonstrates their applicability to real-time applications. An active vibration control （AVC） algorithm for a flexible beam system simulated using the finite difference （FD） method is considered to demonstrate the effectiveness of the proposed methods. A comparative performance evaluation of the proposed design mechanisms is presented and discussed through a set of experiments.

ANALYTIC SENSITIVITY ANALYSIS FORSHAPE OPTIMIZATION

Analytic sensitivity analysis technology for the boundary element method (BEM) is presented, combined with a shape optimization system for structural analysis. A shape optimization was done for an elastomer under planar stress, based on this new algorithm. A multi-object problem was studied as an illustrative example for the programmer, using weighted summing method. The result is feasible.

DESIGN OF RECONFIGURABLE MANUFACTURING SYSTEMS WITH STRONGLY COUPLED NATURE

Today＇s manufacturing cnvironmem forces manufacturing companies to make as many product variations as possible at affordable costs within a short time. Mass customisation is one of most important technologies for companies to achieve their objectives. Efforts to mass customisation should be made on two aspects： （1） To modularize products and make them as less differences as possible; （2） To design manufacturing resources and make them provide as many processes variations as possible. This paper reports our recent work on aspect （2）, i.e. how to design a reconfignrable manufacturing system （RMS） so that it can be competent to accomplish various processes optimally; Reconfignrable robot system （RRS） is taken as an example. RMS design involves architecture design and configuration design, and configuration design is further divided in design analysis and design synthesis. Axiomatic design theory （ADT） is applied to architecture design, the features and issues of RRS configuration design are discussed, automatic modelling method is developed for design analysis, and concurrent design methodology is presented for design synthesis.

AADL2TASM: a Verification and Analysis Tool for AADL Models

Architecture analysis and design language (AADL) is an architecture description language standard for embedded real-time systems and it is widely used in safety-critical applications. For facilitating verification and analysis, model transformation is one of the methods. A synchronous subset of AADL and a general methodology for translating the AADL subset into timed abstract state machine (TASM) were studied . Based on the atlas transformation language (ATL) framework, the associated translating tool AADL2TASM was implemented by defining the meta-model of both AADL and TASM, and the ATL transformation rules. A case study with property verification of the AADL model was also presented for validating the tool.

Recent developments in the structural design and optimization of ITER neutral beam manifold

This paper describes a new design of the neutral beam manifold based on a more optimized support system.A proposed alternative scheme has presented to replace the former complex manifold supports and internal pipe supports in the final design phase.Both the structural reliability and feasibility were confirmed with detailed analyses.Comparative analyses between two typical types of manifold support scheme were performed.All relevant results of mechanical analyses for typical operation scenarios and fault conditions are presented.Future optimization activities are described,which will give useful information for a refined setting of components in the next phase.

Nested case-control analysis with general additive-multiplicative hazard models

This paper discusses the nested case-control analysis under a class of general additive-multiplicative hazard models which includes the Cox model and the additive hazard model as special cases.A pseudo-score is constructed to estimate the regression parameters.The resulting estimator is shown to be consistent and asymptotically normally distributed.The limiting variance-covariance matrix can be consistently estimated by the nested case-control data.A simulation study is conducted to assess the finite sample performance of the proposed estimator and a real example is provided for illustration.

An Intelligent Approach in Design Optimzation Based on Determining Constraints Compatibility

Based on monotonicity analysis and computer symbolic manipulating technique,a procedure for determining constraints compatibility in design optimization hasbeen proposed in this paper. By using the proposed method relationshipsbetween constrains can be determined and the optimization is greatly simplifid.The method is code with intelligent production systems.