3D Parametric Model Research Articles

Estimating 3D human shape under clothing from a single RGB image

Estimation of naked human shape is essential in several applications such as virtual try-on. We propose an approach that estimates naked human 3D pose and shape, including non-skeletal shape information such as musculature and fat distribution, from a single RGB image. The proposed approach optimizes a parametric 3D human model using person silhouettes with clothing category, and statistical displacement models between clothed and naked body shapes associated with each clothing category. Experiments demonstrate that our approach estimates human shape more accurately than a prior method.

3D scanning systems for monitoring the size of mesh implants

The work is devoted to 3D scanning capabilities investigation for controlling the geometric dimensions of cervical spinal implants. Models of cervical implants were modeled in the CAD program “SolidWorks” and were made on rapid prototyping installations RS 6000 and ProJet 1200. Polymer models of implants were used for casting on consumable patterns at the casting unit Inducast. Scanning of polymer models and metal castings was performed using the 3D scanning system Activity 850. The resulting parametric 3D model had a lot of defects and inaccuracies. However, the use of non-contact optical scanning methods greatly simplifies the measurement of the control dimensions of complex profile mesh implants.

Design and Performance Analysis of Vehicle Tyre Pattern Material Using Finite Element Analysis and ANSYS R16.2

As it stands now, rubber has been the main material used in the making of pneumatic vehicle tyres. Speed of the vehicle depends on many factors like steering geometry, inflation pressure, vehicle load, road temperature and environmental conditions. The main aim of this research is to develop a finite element approach and computationally evaluate the performance of a steady-state rolling tyre by changing the tyre tread patterns. The tyre normally composed of rubber and body-ply was investigated with regards to the effect of the inflation pressure. Tyre modeling using six different types of patterns was completed by using Creo parametric 3D modeling software and then the tyre was discretized into small elements through ANSYS R16.2. The rim area of the tyre was fixed and pressure was applied to the inside surface of the rim. Finite element analysis was completed by using ANSYS R16.2 and equivalent stress, contact stress and contact pressure were found out to identify the best tyre pattern. From the final results it was observed that, Pattern-I had good agreement of results as compared to other type of patterns which showed medium frictional stress and contact pressure.

A web-based 3D virtual display framework for warp-knitted seamless garment design

PurposeThe virtual display of 3D garment is one of the most important features in a computer-aided garment design system. The purpose of this paper is to present a novel web-based 3D virtual display framework for the online design of warp-knitted seamless garment using the latest WebGL and HTML5 technologies.Design/methodology/approachBased on the feature-based parametric 3D human body model, the 3D model of skin-tight warp-knitted seamless garment is established using the geometric modeling method. By applying plane parameterization technology, the 3D garment model is then projected into corresponding 2D prototype pattern and a texture-mapping relationship is obtained. Finally, an online 3D virtual display application framework for warp-knitted seamless garment is implemented on modern WebGL-enabled web browsers using the latest WebGL and HTML5 technologies, which allow garment designers to globally access without installing any additional software or plugin.FindingsBased on the 2D/3D model of warp-knitted seamless garment, an online 3D virtual display application running on modern WebGL-enabled web browser is implemented using the latest Javascript, WebGL and HTML5 technologies, which is proven to be an effective way for building the web-based 3D garment CAD systems.Originality/valueThis paper provides a parametric design method for warp-knitted seamless garment 2D/3D model, and web-based online virtual display of 3D warp-knitted seamless garment is implemented for the first time, which establishes the foundation for the web-based online computer-aided warp-knitted seamless garment design system.

CNC Module for Turning: A New CAM Application

The integrated CAM application for the KOMPAS-3D environment known as CNC Module for Turning is considered. This application permits automated development of control programs for numerically controlled lathes. The user may readily adapt the CAM application for specific production conditions and machine tools, thanks to features such as the following: representation of the cutting tools by means of parametric 3D models, the possibility of including fixed CNC cycles in the control programs, and the use of the Python language for programming of the postprocessors.

Designing and Evaluation of Bagasse Powered Preheating Device for Seed Cane Hot-water Treatment Plant

As a solution for the energy crisis facing today, the biomass from the sugarcane industry plays major role as an energy source in developing countries. Sugarcane (Saccarhum officinarum) is a globally important source of commercial sugar, which accounts for over 75 percent of the world sugar production. It is estimated that, 30 percent of wet bagasse is produced in a normal sugar mill. Sugarcane bagasse has a heating value of 16792.44 kJ/kg. There is a high potential for using bagasse as a biomass energy source of agricultural sector when considering its thermal properties and the availability. Due to non-availability of disease-free healthy planting materials, sugarcane productivity in Sri Lanka has decreased. Hot water treatment of sugarcane planting material is practiced to control systemic diseases of sugarcane such as ratoon stunting disease and smut. Operating of the existing hot water treatment plants require high electricity for the initial heating process which is very costly and time consuming. This research is focused on designing and evaluating of a bagasse powered pre-heating device for seed cane hot water treatment plant for saving energy and time. The flue gas generated by burning of bagasse was used as the energy source for steam generation inside the pre-heating device. The pre-heating device was designed by combining the concepts of water tube boiler and shell boiler so that the device is named as the combined steam generator. Specifications of the preheating device were calculated according to the heat energy requirement of feed water, steam and fuel energy. Conceptual design for the new pre-heating device was developed considering the system requirements. Based on the concept, a detail design of each part of the device was developed with properly defined dimensions, using a parametric 3D modeling software and simulation process carried out using finite element analysis (FEA). Then the preheating device was completely assembled with fabricated parts. According to the evaluation results, efficiency of the combined steam generator was 80.14%. So the time and the electric energy consumption are reduced by 37% and 99.17% respectively. Keywords: Seed cane, Bagasse, Hot water treatment, Biomass energy, Steam

Virtual Design of Thick Electrodes for Li-Ion Batteries

Li-Ion batteries are commonly used in portable electronic devices due to their outstanding energy and power density. A remaining issue which hinders the breakthrough e.g. in the automotive sector is the high production cost. Going ‘giga’ is one approach currently pursued but requires large investments. Recently, battery concepts with thick electrodes were presented as attractive alternative1. Batteries with thicker electrodes provide higher theoretical energy densities with only a few electrode layers which reduces production time and cost2.In our contribution we present 3D micro-structure resolved simulations of thick (electrodes > 300µm) Graphite-NMC batteries based on our thermodynamically consistent simulation framework BEST3. The parametrization and validation of our model is presented in a recent publication4 and simulation results agree favourably with experimental data2. As a major problem we identified transport limitations in the electrolyte at comparatively small C-rates2,4. Novel design and operation strategies of the battery and its components are needed to mitigate this issue. In this presentation we will focus on our on-going electrode design studies. Two different design concepts using laser perforation and/or porosity gradients were evaluated regarding their performance at high C-rates. Therefore, multiple realizations of electrode structures were generated with a stochastic 3D geometry generator5. The structures and corresponding electrochemical simulations were validated against tomography and experimental data of model electrodes. The virtual screening of different configurations provides material-structure-function relationships which are a helpful tool for the processing of thick electrodes on larger scales.1. Hopkins, B. J. et al, Component-cost and performance based comparison of flow and static batteries. J. Power Sources 293, 1032–1038 (2015).2. Singh, M. et al, Thick Electrodes for High Energy Lithium Ion Batteries. J. Electrochem. Soc. 162, A1196–A1201 (2015).3. Latz, A. et al, Multiscale modeling of lithium ion batteries: thermal aspects. Beilstein J. Nanotechnol. 6, 987–1007 (2015).4. Danner, T. et al. Thick electrodes for Li-ion batteries: A model based analysis. J. Power Sources 334, 191–201 (2016).5. Westhoff, D. et al. Parametric stochastic 3D model for the microstructure of anodes in lithium-ion power cells. Comput. Mater. Sci. 126, 453–467 (2017). Figure 1

Bridge information modelling (BrIM) for a listed viaduct

Bridge information modelling (BrIM) invokes stakeholder collaboration, supported by policy and process frameworks, combined with interoperable technology, to manage information and enable effective decision making throughout the lifecycle of a bridge asset. This paper considers the application of BrIM for the proposed rehabilitation of a heritage listed viaduct. The structure under consideration is the landmark Chetwynd viaduct in Cork (Ireland), which formed part of the Cork–Bandon railway infrastructure constructed in 1851 and decommissioned in 1961. As with infrastructure of its type, few as-built records exist. Consequently, the geometry, material properties and condition of the existing structure are required to inform the initial feasibility assessment and subsequent design, construction and operation of this viaduct asset. Respective BrIM and traditional approaches to the data capture phase are outlined and compared in terms of time, expertise and deliverables. The significant deliverables from the traditional approach include a three-dimensional (3D) solid model and independent 2D drawings. Significant deliverables achieved using a BrIM approach include an intelligent parametric 3D model and associated 2D drawings, as well as integrated datasets representative of the ‘as-is’ structure. Based on reported research, the initial effort and time expended on model creation in particular will enable significant future benefits.

MODELING THE DECAY IN AN HBIM STARTING FROM 3D POINT CLOUDS. A FOLLOWED APPROACH FOR CULTURAL HERITAGE KNOWLEDGE

Abstract. The recent trends in architectural data management imply the scientific and professional collaborations of several disciplines involved in the design, restoration and maintenance. It seems an achieved concept that, in the next future, all the information connected to new interventions or conservation activities on historical buildings will be managed by using a BIM platform. Nowadays the actual range or image based metric survey techniques (mainly produced by using Terrestrial Laser Scanner or photogrammetric platform today more based on projective geometry) allow to generate 3D point clouds, 3D models, orthophotos and other outputs with assessed accuracy. The subsequent conversion of 3D information into parametric components, especially in an historical environment, is not easy and has a lot of open issues. According to the actual BIM commercial software and to the embedded tools or plugin, the paper deals with the methodology followed for the realization of two parametric 3D models (Palazzo Sarmatoris and Smistamento RoundHouse, two historical building in the north-west part of Italy). The paper describes the proposed workflow according to the employed plug-in for automatic reconstruction and to the solution adopted for the well-known problems connected to the modeling phase such as the vaults realization or the 3D irregular surfaces modeling. Finally, the studied strategy for mapping the decay in a BIM environment and the connected results with the conclusions and future perspectives are critically discussed.

Analytical weight estimation of landing gear designs

Landing gear weight calculations can be carried out using statistical or analytical methods. Statistical methods were used in the past and offered quick group weights. However, they are not capable of computing accurately the weight of landing gears, which have special geometries and performance. In this work, landing gear weight is computed using analytical methods based on parametric 3D models. The procedure established by Kraus and Wille is applied as a baseline so as to create a procedure capable of dealing with landing gear weight calculations. This method is designed to be as flexible as possible, giving the user the freedom to modify many options and parameters and integrate landing gear design into Robust Aircraft Parametric Interactive Design.

Roboticus tignarius: robotic reproduction of traditional timber joints for the reconstruction of the architectural heritage of Valparaíso

The architectural heritage of Valparaiso, Chile is disappearing before our eyes while all the conventional resources to reverse this situation seem to have been exhausted. A large portion of the existing historic building substance consists of timber frames that succumb one after another to weathering, termites and structural fires. The acute shortage of traditional timber framers and a weak local heritage industry feed investors’ disinterest in preserving the original structural conception of these timber-framed buildings when they need restoration or rehabilitation. There is a need for technological innovation enabling one-off production of complex-skilled joinery at competitive costs. Robotic machining emerges as a flexible and customizable alternative to the missing timber framers and the insensible substitution of original timber joints for metal fasteners. We present a proof-of-concept of parametric 3D modelling and robot path generation using a single visual scripting environment integrated to CAD software that requires no knowledge of robot programming and might encourage designers as well as small- and medium-sized manufacturers to develop a local heritage industry. Several classes of timber joints found in Valparaiso were parameterized and instances thereof manufactured by a six-axis industrial robot with a spindle mounted thereon to gain empirical knowledge of the entire process. Experimental results show that procedural modelling of parts, assemblies, and tool paths in the tested visual scripting environment is time-consuming and rather complicated for conventional architectural thinking, but is largely compensated by its software and hardware interaction potential.

Performance Simulation Integrated in Parametric 3D Modeling as a Method for Early Stage Design Optimization—A Review

During the last decades, standards on building construction have risen sharply to integrate new, ambitious demands regarding energy efficiency, as well as thermal and optical comfort in the design procedure. Building simulation software assists in the accurate calculation of a hypothetical or existing building’s performance on several aspects; but they are, in their vast majority, assessment-oriented, rather than focused on dynamically supporting the decision-making procedure. During the last two decades, a clear shift of design professionals and academia towards addressing performance issues from the conceptual stages of a building’s design is observed. In this review, the methodology of performance-driven design optimization using computational/parametric design and optimization is presented, and the core literature available on the topic is reviewed in order to identify the current status, different approaches, obstacles, and areas of future research on the subject. The review findings confirm that there is enormous potential for the design of better-performing buildings using this technique, but there are still many obstacles to overcome and areas for future research.

Modeling algae powered neighborhood through GIS and BIM integration

This paper aims to propose a modeling method for algae powered neighborhoods through GIS-BIM integration. In the first part of the paper, the applicability of different types of algae systems in an urban neighborhood are studied. The various systems of algae provide different strengths and weakness that affect their performance and suitability for given urban scenarios. Through extensive literature review, the variables that affect the performance of the micro-algae in the built environment are identified, with a focus on flat-panel photo bio-reactors and tubular photobioreactors. A previous GIS model for data management, performance analysis and design of the algae systems is reviewed [1], which shows its limitations in managing fine-grained structures and functions of algae systems. A bottom-up BIM approach to deal with these limitations is further explored. The algae-embedded built environment can be modeled in the parametric 3D BIM and Rhinoceros with a set of building parameters for the roof, façade, window to wall ratio, etc. Subsequently, solar exposure on building surfaces, the use of the buildings and their respective façade types would be studied. Parametric 3D models of the buildings allows for faster design modification and the creation of multiple design options. These models can be used to perform energy analysis using the parametric energy analysis tool to check for building energy use intensity (EUI). The bottom-up approach explored in this research design aims to facilitate visualization and analysis of the built environment and gauge the productivity of microalgae. Finally, a platform for BIM –GIS integration and its possibility is explored in this paper.

POINT CLOUD DERIVED FROMVIDEO FRAMES: ACCURACY ASSESSMENT IN RELATION TO TERRESTRIAL LASER SCANNINGAND DIGITAL CAMERA DATA

Abstract. The use of image sequences in the form of video frames recorded on data storage is very useful in especially when working with large and complex structures. Two cameras were used in this study: Sony NEX-5N (for the test object) and Sony NEX-VG10 E (for the historic building). In both cases, a Sony α f = 16 mm fixed focus wide-angle lens was used. Single frames with sufficient overlap were selected from the video sequence using an equation for automatic frame selection. In order to improve the quality of the generated point clouds, each video frame underwent histogram equalization and image sharpening. Point clouds were generated from the video frames using the SGM-like image matching algorithm. The accuracy assessment was based on two reference point clouds: the first from terrestrial laser scanning and the second generated based on images acquired using a high resolution camera, the NIKON D800. The performed research has shown, that highest accuracies are obtained for point clouds generated from video frames, for which a high pass filtration and histogram equalization had been performed. Studies have shown that to obtain a point cloud density comparable to TLS, an overlap between subsequent video frames must be 85 % or more. Based on the point cloud generated from video data, a parametric 3D model can be generated. This type of the 3D model can be used in HBIM construction.

Opposed-Piston Crankshaft System Dynamics Simulation and Durability Analysis in a Neotype Two-Stroke Diesel Engine

For the opposed-piston and opposed-cylinder (OPOC) diesel engine with higher power density, recently it has drawn even more attentions than ever in several developed countries, such USA and Germany, et al, which is regarded as a technical innovation to further reduce emission, and decrease fuel consumption, attributed to outstanding thermal efficiency and engine package downsizing. To explore the interrelation of this special crank system in concept design stage, the multi-body dynamics and durability of the piston-opposed crankshaft system was investigated. Firstly the optimized function model of the unique crankshaft system in an OP2S (Opposed-piston two stroke) engine was established. Then it was to figure out the influence of all structural design parameters on OPE crankshaft averaged output torque, respectively. The calculated results show that the initial crank angle difference between inner crank web and outer crank web was the most critical contributor to elevate the averaged torque output than other structural parameters. The parametric 3D model of crankshaft system was refreshed automatically based on the optimized variables. Finally an OPE crankshaft prototype was manufactured and bend fatigue experiment was carried out in a relevant laboratory to obtain the material S-N Curve. The HCF (High Cycle Fatigue) result was indicated that the minimum safety factor on crank journal fillets can reach relevant estimation criterion without crankshaft failure occurring for an engine speed sweep.

Impact of the Exhaust Geometry on Flow Losses in a High-Pressure Steam Turbine

The design of modern steam turbines for power plant applications is steering towards higher efficiencies. A considerable contribution to this aim is expected from a reduction of flow losses in turbine intakes and exhausts. The present study therefore deals with the optimisation of the exhaust of a high-pressure (HP) turbine. In the first part of this study a numerical model is presented which allows for a precise representation of the exhaust flow. This computational fluid dynamics (CFD) model has been validated with a fair amount of experimental data from a test rig. For the second part of the study comprehensive numerical investigations have been carried out, considering the major geometrical parameters of such a geometry. In order to minimize the effort in design time and preprocessing a fully parametric 3D model of the geometry is created to prepare the different design variations. The results of these simulations allow to assess the performance differences of given exhaust designs in the early design phase without the need for expensive CFD simulations. Finally a potential for improvement of 300 kW for a 800 MW power plant is shown by means of a comparison of an optimised design to the baseline geometry.

Parametric stochastic 3D model for the microstructure of anodes in lithium-ion power cells

The microstructure of anodes in lithium-ion batteries has a strong influence on their electrochemical performance and degradation effects. Thus, optimizing the morphology with respect to functionality is a main goal in battery research. Doing so experimentally in the laboratory causes high costs with regard to time and resources. One way to overcome this problem is the usage of parametric 3D microstructure models, which allow the realization of virtual morphologies on the computer. The functionality of microstructures generated with such models can be investigated by means of numerical transport simulations. The results of this procedure, which is called virtual materials testing, can be used to design anodes with improved morphologies that lead to a better electrochemical performance. Recently, a particle-based stochastic microstructure model for anodes in lithium-ion energy cells has been proposed. In the present paper, an extension of this model to describe the morphology of anodes in power cells, whose structure strongly differs from energy cell anodes, is introduced. The extensions include techniques to model anisotropic morphologies with a low volume fraction of the particle phase and strongly irregular particle shapes. The model is fitted to 3D image data of a power cell anode and validated using morphological image characteristics. Furthermore, we show examples of modifications of our microstructure model that can be made for generating further virtual morphologies. Finally, we briefly explain how electrochemical characteristics can be estimated using thermodynamically consistent transport theory. To illustrate this, we compute the cell potential over time during lithiation for image data of real microstructures as well as corresponding microstructures simulated by our model.

Stochastic 3D modeling of complex three-phase microstructures in SOFC-electrodes with completely connected phases

A parametric stochastic 3D model for the description of complex three-phase microstructures is developed. Such materials occur for example in anodes of solid oxide fuel cells (SOFC) which consist of pores, nickel (Ni) and yttria-stabilized zirconia (YSZ). The model is constructed using tools from stochastic geometry. More precisely, we model the backbones of the three phases by a certain class of random geometric graphs called beta-skeletons. This allows us to reproduce complete connectivity of all three phases as observed in experimental image data of a pristine Ni–YSZ anode as well as the prediction of volume fractions by model parameters. Finally a slightly generalized version of this model enables a good fit to experimental image data with respect to transport relevant microstructure characteristics and the length of triple phase boundary. Model validation is performed by comparing effective transport properties from finite element (FE) simulations based on 3D-data from the stochastic model and from tomography of real Ni–YSZ anodes. Moreover, the virtual, but realistic Ni–YSZ microstructures can be used for investigating the quantitative influence of microstructure characteristics on various physical properties and consequently on the performance of the anode material.

Parametric analysis and systems design of dynamic photovoltaic shading modules

AbstractShading systems improve building energy performance and occupant comfort by controlling glare, natural lighting, and solar gain. Integrating PV (photovoltaics) in shading systems opens new opportunities for BIPV (building integrated photovoltaics) on façades. A key problem of such systems is mutual shading among PV modules as it can lead to electrical mismatch losses and overheating effects. In this work, we present a new modeling framework, which couples parametric 3D with high‐resolution electrical modeling of thin‐film PV modules to simulate electric energy yield of geometrically complex PV applications. The developed method is able to predict the shading pattern for individual PV modules with high spatio‐temporal resolution, which is of great importance for electrical system design. The methodology is applied to evaluate the performance of different dynamic BIPV shading system configurations, as well as its sensitivity to façade orientation and module arrangement. The analysis shows, that there is a trade‐off between tracking performance and mutual shading of modules. Distance between modules is a critical parameter influencing the amount of mutual shading and hence limiting solar irradiation and electricity generation of PV shading systems using solar tracking. Planning of module string configuration, PV cell orientation, and location of bypass diodes according to partial shading conditions, reduces electrical mismatch losses and results in significantly higher electricity generation. The integration of parametric 3D and electrical modeling opens new possibilities for PV system design and dynamic control optimization. Though the analysis focuses on BIPV, the method is useful for the planning and operation of solar tracking systems in general.

Design Criteria Modeling - Use of Ontology-Based Algorithmic Modeling to Represent Architectural Design Criteria at the Conceptual Design Stage

ABSTRACTThis paper proposes an ontology-based parametric modeling tool termed “Design Criteria Modeling (DCM),” which applies a graphic predicate tool and semantic ontologies of architectural topology. DCM aims to help architects in representing, exploring, and validating design criteria by means of parametric 3D model at the early design stage. By applying a semantic ontology reasoner, DCM can help architects to determine whether conceptual models meet the semantic ontology of proposed design criteria.