Development of a 3D Conceptual Design Environment Using a Head Mounted Display Virtual Reality System

Engineering design is a resource intensive process with over half of a product’s total cost being attributed to design stage decisions. Developing product designs often involves creating complex 3D models in a 2D environment, a non-trivial task. This paper details a proof of concept VR environment displayed in a commodity HMD, specifically the HTC Vive. The environment allows a user to create full-scale, 3D, product geometry at the conceptual phase of the design process. The conceptual design environment contains a World-in-Miniature (WIM) model for enhanced usability. This method allows a user to efficiently manipulate full-scale geometry by adjusting the corresponding parts on a WIM model. Free-form mesh deformation was also implemented to provide designers with flexibility and efficiency not found in traditional design packages. Vital design metrics (e.g., cost, weight, and center of mass) were incorporated to allow a user to perform preliminary design analysis to assess product feasibility. Throughout the development process, the unique challenges and affordances associated with commodity HMDs were identified, explored, and discussed in this paper. Ultimately, the VR application discussed in this paper allows the user to easily create, assess, and view conceptual 3D designs without the constraints of traditional CAD software.

Gas Turbine Design and Matching Research of Waste Heat Recovery System for Marine Diesel Engine

With the emphasis on energy and environmental protection,energy-conservation and emission-reduction become vital issues for industrial development.Moreover,with the development of legislation on marine environment,the marine diesel engine has become focusing on energy saving and emission reduction for ships.For low-speed diesel engines under high load,waste heat from exhaust gas can be recovered by the compact and efficient gas turbine.In this paper,the matching design research between low speed diesel engine and gas turbine is carried out.To balance efficiency and compactness,the impeller was adjusted and generated by ANSYS BLADEGEN,based on 1D thermodynamic design.And the 1D calculation is similar to the ANSYS CFX simulation result:the total-static efficiency is 73.8%compared to 76.7%.Moreover,the flow separation happened at the impeller suction side and created vortex due to the high incidence angle.The off-design operating point simulation of the turbine shows though the pressure ratio increase will cause the efficiency to decline a little,the total shaft power rises.In sum,this paper worked out a power turbine suitable for a low-speed diesel engine according to the turbine character matching design and simulation,which provides foundation to the construction of a steady operation of waste heat recovery system for marine diesel engine.

Integration system research and development for three-dimensional laser scanning information visualization in goaf

An integration processing system of three-dimensional laser scanning information visualization in goaf was developed. It is provided with multiple functions, such as laser scanning information management for goaf, cloud data de-noising optimization, construction, display and operation of three-dimensional model, model editing, profile generation, calculation of goaf volume and roof area, Boolean calculation among models and interaction with the third party soft ware. Concerning this system with a concise interface, plentiful data input/output interfaces, it is featured with high integration, simple and convenient operations of applications. According to practice, in addition to being well-adapted, this system is favorably reliable and stable.

Stability analysis of underground engineering based on multidisciplinary design optimization

Aiming at characteristics of underground engineering,analyzed the feasibility of Multidisciplinary Design Optimization (MDO) used in underground engineering,and put forward a modularization-based MDO method and the idea of MDO to resolve problems in stability analysis,proving the validity and feasibility of using MDO in underground engi- neering.Characteristics of uncertainty,complexity and nonlinear become bottle-neck to carry on underground engineering stability analysis by MDO.Therefore,the application of MDO in underground engineering stability analysis is still at a stage of exploration,which need some deep research.

A System Status Definition to Improve Behavior Description in Specifications Based on Constructal Law

System behavior description using states faces problems like state explosion, lack of clear definition of state, state identification and coordination between multiple agents. The goals of this work are to ease design activity, to reduce engineering efforts, and to mitigate project risks. The proposed way is to improve information flow during design by adding definitions and some protocols or rules for communicating a specification or design description. This work presented an objective definition of system status (way of interaction with the rest of the world) along other concepts. This work focused in definitions as mind entities and their importance to rationalize work and mitigate project risks during design. This article presented some simple examples to illustrate the advantages of each aspect of proposed definition of system status and discussed limits and exceptions for such definition. The key finding was the proposed definition which was the simplest while keeping completeness at a given product breakdown level. Such definition of status enforced formal segregation of needs and solutions, and eased the inclusion of behavior definition in specifications.

Innovative Techniques Unveiled in Advanced Sheet Pile Curtain Design

This thorough review explores the complexities of geotechnical engineering, emphasizing soil-structure interaction (SSI). The investigation centers on sheet pile design, examining two primary methodologies: Limit Equilibrium Methods (LEM) and Soil-Structure Interaction Methods (SSIM). While LEM methods, grounded in classical principles, provide valuable insights for preliminary design considerations, they may encounter limitations in addressing real-world complexities. In contrast, SSIM methods, including the SSI-SR approach, introduce precision and depth to the field. By employing numerical techniques such as Finite Element (FE) and Finite Difference (FD) analyses, these methods enable engineers to navigate the dynamics of soil-structure interaction. The exploration extends to SSI-FE, highlighting its essential role in civil engineering. By integrating Finite Element analysis with considerations for soil-structure interaction, the SSI-FE method offers a holistic understanding of how structures dynamically interact with their geotechnical environment. Throughout this exploration, the study dissects critical components governing SSIM methods, providing engineers with tools to navigate the intricate landscape of geotechnical design. The study acknowledges the significance of the Mohr-Coulomb constitutive model while recognizing its limitations, and guiding practitioners toward informed decision-making in geotechnical analyses. As the article concludes, it underscores the importance of continuous learning and innovation for the future of geotechnical engineering. With advancing technology and an evolving understanding of soil-structure interaction, the study remains committed to ensuring the safety, stability, and efficiency of geotechnical structures through cutting-edge design and analysis techniques.

A Multi-strategy Improved Snake Optimizer Assisted with Population Crowding Analysis for Engineering Design Problems

Snake Optimizer(SO)is a novel Meta-heuristic Algorithm(MA)inspired by the mating behaviour of snakes,which has achieved success in global numerical optimization problems and practical engineering applications.However,it also has certain drawbacks for the exploration stage and the egg hatch process,resulting in slow convergence speed and inferior solution quality.To address the above issues,a novel multi-strategy improved SO(MISO)with the assistance of population crowding analysis is proposed in this article.In the algorithm,a novel multi-strategy operator is designed for the exploration stage,which not only focuses on using the information of better performing individuals to improve the quality of solution,but also focuses on maintaining population diversity.To boost the efficiency of the egg hatch process,the multi-strategy egg hatch process is proposed to regenerate individuals according to the results of the population crowding analysis.In addition,a local search method is employed to further enhance the convergence speed and the local search capability.MISO is first compared with three sets of algorithms in the CEC2020 benchmark functions,including SO with its two recently discussed variants,ten advanced MAs,and six powerful CEC competition algorithms.The performance of MISO is then verified on five practical engineering design problems.The experimental results show that MISO provides a promising performance for the above optimization cases in terms of convergence speed and solution quality.

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.

CONCURRENT PRODUCTION ENGINEERING SYSTEM FOR BUFFER SIZE AND FLEXIBLE TRANSFER LINE LAYOUT DESIGN

In this paper we propose a COncurrent Production Engineering System （COPES） for the flexible transfer line （FTL） layout design in a restricted area. COPES first determines the buffer size in front of the bay of each machine tool in the FTL and then initializes a computer aided design （CAD） system to draw the FTL in a restricted area. We develop a set of modules systems which have been integrated into a single framework, in accordance with the practice of concurrent engineering. Concurrent engineering involves the cooperation of these activities. It＇s expected that the developed COPES can improve the cooperation between production engineers＇ and the plant designer. This can be done by enabling the production engineers＇ to make better decision regarding FTL buffer size.

Convergence Analysis of the Numerical Solution for Cathode Design of Aero-engine Blades in Electrochemical Machining

As a main difficult problem encountered in electrochemical machining （ECM）, the cathode design is tackled, at present, with various numerical analysis methods such as finite difference, finite element and boundary element methods. Among them, the finite element method presents more flexibility to deal with the irregularly shaped workpieces. However, it is very difficult to ensure the convergence of finite element numerical approach. This paper proposes an accurate model and a finite element numerical approach of cathode design based on the potential distribution in inter-electrode gap. In order to ensure the convergence of finite element numerical approach and increase the accuracy in cathode design, the cathode shape should be iterated to eliminate the design errors in computational process. Several experiments are conducted to verify the machining accuracy of the designed cathode. The experimental results have proven perfect convergence and good computing accuracy of the proposed finite element numerical approach by the high surface quality and dimensional accuracy of the machined blades.

Optimal Port Design Minimizing Standing Waves with A Posteriori Long Term Shoreline Sustainability Analysis

Optimization theory is applied to a coastal engineering problem that is the design of a port.This approach was applied to the redesign of La Turballe Port in order to increase the exploitable surface area and simultaneously reduce the occurrence of long waves within the port.Having defined the cost function as a weighted function of wave amplitude and with the chosen parameterization of the port,results show that an extended jetty and a widened mole yield a unique optimal solution.This work demonstrates that numerical optimization may be quick and efficient in the identification of port solutions consistent with classic engineering even in the context of complex problems.

Investigation into precision engineering design and development of the next-generation brake discs using Al/SiC metal matrix composites

Substantially lightweight brake discs with high wear resistance are highly desirable in the automotive industry.This paper presents an investigation of the precision-engineering design and development of automotive brake discs using nonhomogeneous Al/SiC metal-matrixcomposite materials.The design and development are based on modeling and analysis following stringent precision-engineering principles,i.e.,brake-disc systems that operate repeatably and stably over time as enabled by precision-engineering design.The design and development are further supported by tribological experimental testing and finite-element simulations.The results show the industrial feasibility of the innovative design approach and the application merits of using advanced metal-matrix-composite materials for next-generation automotive and electric vehicles.

Undergraduate Design and Analysis of a LEED Certified Building

In this technical and educational research endeavor, a diverse group of civil engineering students took on the role of creating the means and methods of producing a successful building design. Architectural, structural, and environmental designs were primarily performed. This was followed by detailed cost analysis with the intent of providing a realistic cost comparison by pricing the intended building, using traditional material and typical building methods, versus pricing the building using recycled material and new present-day technology. Some green features needed to achieve a LEED (Leadership in Energy and Environmental Design) gold certification were considered and applied. It is shown that producing a green building is more costly in present circumstances;however, the additional cost due to greenification pays itself off throughout the years giving in return saving features. Even though the design of a green building comes with detailed planning and costly material, it does generate benefits for the building owner, the society, and most importantly the environment.

Full Cycle Cold Flow Analysis of the Effect of Twin Swirl Combustion Chamber Design in a Diesel Engine

New designs and adaptation methods are experimented to ensure compliance to ever increasing emissions and efficiency requirements of modern diesel engines. Piston head structure which influences the mixing rate and timing of the fuel within in the combustion chamber is known to enable increase in combustion efficiency and thus lower emission rates. In this paper, computation analysis of flow within a diesel engine cylinder with a twin swirl combustion chamber design throughout a full cycle is presented. The results obtained indicate that the effect of the twin swirl combustion chamber on the cold flow conditions is noteworthy and further analysis together with experiments may reveal information that may prove to be useful in further new designs.

考虑锚杆预应力作用下隧道围岩力学分析及参数设计

隧道工程中锚杆设计多依靠经验法和类比法,为研究预应力锚杆支护体系下围岩的力学效应,建立预应力锚杆与围岩力学耦合模型,考虑围岩开挖损伤效应,通过弹塑性力学理论推导出隧道开挖后围岩应力分布及径向位移解析表达式,采用有限差分软件FLAC3D进行算例验证并分析预应力锚杆参数对围岩状态的影响。研究结果表明:理论解析和数值模拟中最大切向应力和围岩塑性区半径分别为4.77 MPa、15 m和4.49 MPa、15.86 m,理论解析与数值模拟所计算隧道围岩应力分布、位移基本一致,在Ⅳ、Ⅴ级围岩地层中验证了理论解析解的合理性;随着预紧力增大,处于塑性区的围岩径向位移及塑性区半径逐渐减小,弹性区基本不受影响;当锚杆自由段长度位于塑性区时,随着锚杆长度增加,围岩塑性区径向位移及塑性区半径逐渐减小。在实际工程中应尽量增大锚杆预紧力,锚杆长度增加对围岩位移以及塑性区的发展控制效果有限,应控制锚杆自由段长度在塑性区内。

基于专利布局和TRIZ的防滴水折叠伞设计研究

为解决折叠伞在使用后存在的雨水处理不便等问题,采用TRIZ创新方法设计了一种新型折叠伞。并对设计方案进行专利布局保护。首先,选取关键词和IPC分类号构建检索式,利用专利搜索引擎确定全球折叠伞专利并分析技术构成;然后,运用TRIZ创新方法对折叠伞进行创新设计,得到防滴水折叠伞核心专利;最后,结合专利布局的组合类型,围绕核心专利对折叠伞进行降落伞型的组合式专利布局。结果表明,所设计的防滴水折叠伞可实现雨水的便捷处理且便于收纳,并通过专利布局保护对核心专利进行了有效保护。研究结果为制伞企业构建完善创新设计和专利防御体系提供了一种有效方法。

斯特林机帽式密封性能分析及回归参数优化设计

为改善斯特林机活塞杆帽式密封性能,首先采用数值仿真分析了5 MPa工质压力下其静、动态力学特性,从而获取了O型圈内径尺寸L_(N)、C型环径向壁厚T和装配过盈量S这3个关键结构参数对密封性能的影响规律。在此基础上,利用回归设计法以配伍面最大接触压力平稳且密封可靠为优化目标,对密封结构的上述3个关键参数进行优化设计以确定其最佳匹配方案,最后通过密封试验台验证了本文优化设计方法的准确性和普适性。结果表明:活塞杆与C型环密封面中间区域上最大接触压力随L_(N)和S的增大而增大,但随T的增大而减小;通过估计回归系数和方差分析(ANOVA)发现,L_(N)对密封性能影响最为显著、S次之、T影响最小;L_(N)和T、L_(N)和S交互项对响应显著,而T和S交互项对响应不显著;当L_(N)为13.745 mm、T为0.40 mm和S为0.020 mm时,优化密封件对应的正行程最大接触压力为9.01 MPa、回程为9.75 MPa,较工程在用密封件(L_(N)=13.780 mm、T=0.50 mm、S=0 mm)最大接触压力分别降低了14.7%和25.5%。实验进一步验证了优化密封件的密封性能和使用寿命均优于工程在用密封件,并且在不同工质压力下优化密封件的接触压力均匀性更好,减摩延寿效果显著,充分证明本文性能分析与优化设计方法准确有效。

面向复杂工程问题的算法系列课程教学案例选择与设计方法探讨

案例教学是算法系列课程行之有效的一种教学方式,有效的教学案例是案例教学取得成功的重要标志。针对教学案例选取不具代表性、案例分析不到位等问题,该文提出相应的解决方案。该方案从复杂工程问题与教学案例之间的关系入手,围绕如何解决复杂工程问题组织教学过程,形成“选择案例、分析案例、形成解题思路、撰写算法、编写程序、运行程序、验证案例”的案例教学过程,提出案例选择等7个原则,以及基于枚举法的教学案例分析方法,举例说明论文所提方法的具体实施过程。该文所提原则和方法对其他课程教学案例的选择与分析具有一定的借鉴意义。

人参皂苷Re的分析与制备综合性实验设计

针对我校应用化学专业工程教育认证申报中存在的专业实验部分教学内容更新不足,无法与现代企业技术和最前沿专业知识同步的现状,在现代仪器分析课程教学过程中,开发了人参皂苷Re的分析与制备的综合设计性实验项目。通过文献调研与分析、实验方案设计、产品制备与分析、数据处理等教学环节,培养学生以更宽的视角关注本专业相关知识的发展,能够运用所学知识与实验技能分析和解决科研实践与生产过程中的实际问题,在此过程中,全面提升学生综合性能力,即会分析问题、能找到科学的方法,最终解决实际问题的能力,满足工程教育专业认证背景下对于人才培养的要求。

成组立模成型机模板结构优化设计研究

混凝土预制构件成组立模成型机(简称成组立模)是一种新型的生产混凝土预制构件的设备。为了提高成组立模台面的振动效果和承载能力,本研究以成组立模模板结构为研究对象,提出了一种拓扑优化新兴设计与响应面法结合的优化设计理论。首先,基于变密度法对成组立模模板结构加强筋布局进行拓扑优化设计,得到了加强筋最佳的材料分布形式,以此对成组立模模板结构进行了结构优化设计。为得到最佳的加强筋设计参数,采用中心组合试验设计,建立模板结构最大位移、最大等效应力的响应面模型。利用多目标遗传算法对响应面模型进行优化求解,得出加强筋各参数最优的组合方案。有限元分析结果表明:与初始方案相比,优化设计方案提高了台面的刚度和强度,同时改善了模板结构的振动特性,并提高了混凝土预制构件的成型质量。该研究为进一步推进成组立模的研究提供了理论指导。