Digital Mock-up Research Articles

Particular risk analysis: impact on hybrid aircraft design

Purpose – This document presents a Particular Risks Assessment (PRA) performed on an Uncontained Engine Rotor Failure (UERF) event for the new aircraft design hybrid Extremely Short Take Off and Landing All Surface (ESTOLAS) aircraft. All three propellers of the ESTOLAS (one hub propeller and two feed propellers) are evaluated for their impact on the aircraft in case of an UERF. The purpose of this paper is to present an illustration of the safety analysis and its requirement in new aircraft development. Design/methodology/approach – The methodology used is in accordance with the aerospace industry safety standard Society of Automobile Engineers (SAE) Aerospace Recommended Practices (ARP) 4,761 (Guidelines and Methods for Conducting the Safety Assessment Process on Civil Airborne Systems and Equipment). Trajectory analyses are used on a digital mock-up of the aircraft to simulate the movement of the propeller blade fragments and its effect on the aircraft and its systems. Findings – The paper provides an insight into the industry practice of performing PRA on new aircraft designs. The study identifies safe and unsafe regions of the aircraft, with the UERF event in mind. Technical solutions are suggested to minimize the damage to the aircraft and its systems. Originality/value – This document fulfills the originality criterion, since it is an analysis performed on a new aircraft design – the ESTOLAS.

Simulation Advancement in Automotive Development: A Brief Review

The automotive development process is advancing through the utilization of CAD/CAM/CAE. This advancement is being enhanced by proper utilization of CAD/CAM integration, Digital prototyping and Digital mock-up. Until recently, CAD has played the leading role for the digitalization of automotive development. However, recent trend shows that, the leading role is shifted from CAD to analysis simulation. Three-dimensional design, which utilizes digital mock-up, is becoming the main tool for product design. Here, the functional capability and predictive assessment by CAE is the core technology. In addition, this supporting role is helping to realize the concurrent engineering in production engineering field.

Disassembly operations’ efficiency evaluation in a virtual environment

Disassembly operations play a very important role during the initial design phase of industrial products. The available disassembly evaluation methods today seldom make disassembly as the preferred end-of-life solution for the reuse of parts or components in an economically sustainable way for lower value products. In virtual environment (VE), for instance, a human model is often involved in a digital mock-up model for assembly/disassembly (A/D) evaluation. However, it has limited application areas because of the high cost investment. Focusing on the evaluation of disassembly operations in a VE, a method based on five new criteria – visibility of a part, disassembly angles, number of tools’ changes, path orientation changing, and sub-assembly stability – is proposed here. All five criteria are presented by automatically calculated dimensionless coefficients, thus allowing the evaluation of the complexity of disassembly sequences in a VE. For this purpose, a mixed virtual reality disassembly environment based on Python programming language has been developed, using Visualisation Toolkit and Open Dynamics Engine libraries. The results of the analysis and findings demonstrate the feasibility of the proposed approach thus providing significant assistance for the evaluation of disassembly sequences during Product Development Process.

Innovative design for FAST divertor compatible with remote handling, electromagnetic and mechanical analyses

Divertor is a crucial component in Tokamaks, aiming to exhaust the heat power and particles fluxes coming from the plasma during discharges. This paper focuses on the optimization process of FAST divertor, aimed at achieving required thermo-mechanical capabilities and the remote handling (RH) compatibility. Divertor RH system final layout has been chosen between different concept solutions proposed and analyzed within the principles of Theory of Inventive Problem Solving (TRIZ). The design was aided by kinematic simulations performed using Digital Mock-Up capabilities of Catia software. Considerable electromagnetic (EM) analysis efforts and top-down CAD approach enabled the design of a final and consistent concept, starting from a very first dimensioning for EM loads.In the final version here presented, the divertor cassette supports a set of tungsten (W) actively cooled tiles which compose the inner and outer vertical targets, facing the plasma and exhausting the main part of heat flux. W-tiles are assembled together considering a minimum gap tolerance (0.1–0.5mm) to be mandatorily respected. Cooling channels have been re-dimensioned to optimize the geometry and the layout of coolant volume inside the cassette has been modified as well to enhance the general efficiency.

Shoulder kinematics and spatial pattern of trapezius electromyographic activity in real and virtual environments.

The design of an industrial workstation tends to include ergonomic assessment steps based on a digital mock-up and a virtual reality setup. Lack of interaction and system fidelity is often reported as a main issue in such virtual reality applications. This limitation is a crucial issue as thorough ergonomic analysis is required for an investigation of the biomechanics. In the current study, we investigated the biomechanical responses of the shoulder joint in a simulated assembly task for comparison with the biomechanical responses in virtual environments. Sixteen male healthy novice subjects performed the task on three different platforms: real (RE), virtual (VE), and virtual environment with force feedback (VEF) with low and high precision demands. The subjects repeated the task 12 times (i.e., 12 cycles). High density electromyography from the upper trapezius and rotation angles of the shoulder joint were recorded and split into the cycles. The angular trajectories and velocity profiles of the shoulder joint angles over a cycle were computed in 3D. The inter-subject similarity in terms of normalized mutual information on kinematics and electromyography was investigated. Compared with RE the task in VE and VEF was characterized by lower kinematic maxima. The inter-subject similarity in RE compared with intra-subject similarity across the platforms was lower in terms of movement trajectories and greater in terms of trapezius muscle activation. The precision demand resulted in lower inter- and intra-subject similarity across platforms. The proposed approach identifies biomechanical differences in the shoulder joint in both VE and VEF compared with the RE platform, but these differences are less marked in VE mostly due to technical limitations of co-localizing the force feedback system in the VEF platform.

Functional restructuring of CAD models for FEA purposes

Purpose – Preparing digital mock-ups (DMUs) for finite element analyses (FEAs) is currently a long and tedious task requiring many interactive CAD model transformations. Functional information about components appears to be very useful to speed this preparation process. The purpose of this paper is to shows how DMU components can be automatically enriched with some functional information. Design/methodology/approach – DMUs are widespread and stand as reference model for product description. However, DMUs produced by industrial CAD systems essentially contain geometric models, which lead to tedious preparation of finite element Models (FEMs). Analysis and reasoning approaches are developed to automatically enrich DMUs with functional and kinematic properties. Indeed, geometric interfaces between components form a key starting point to analyze their behaviors under reference states. This is a first stage in a reasoning process to progressively identify mechanical, kinematic as well as functional properties of components. Findings – Inferred semantics adds up to the pure geometric representation provided by a DMU and produce also geometrically structured components. Functional information connected to a structured geometric model of a component significantly improves FEM preparation and increases its robustness because idealizations can take place using components’ functions and components’ structure helps defining sub-domains of FEMs. Research limitations/implications – Future research will carry on improving algorithms for geometric interfaces identification, processing a wider range of component functions, which will contribute to a formalization of the concept of functional consistency of a DMU. Originality/value – Simulation engineers benefit from this automated enrichment of DMUs with functional information to speed up the preparation of FEAs of large assemblies.

PLM Based Approach to the Industrialization of Aeronautical Assemblies

The design processes of an aircraft are highly complex and involve a large number of multidisciplinary teams. The current organizational, methodological and technological model, based on concurrent engineering working methods, creates a gap between functional design engineering and industrial design engineering. Such gap is both at the information management level and at communication level, and creates inefficiencies in the working processes. Airbus Military launched the CALIPSOneo project to investigate how to improve the current industrialization design processes and to facilitate a collaborative working environment to the multidisciplinary design teams. As a result of the CALIPSOneo project, PLM tools were adapted to develop working methods based on collaborative engineering, and particularly to develop the industrial Digital Mock-Up (iDMU). Such iDMU contains information of the product, of the assembly processes and of the resources needed during the execution of such processes. iDMU, facilitates the implementation of collaborative working procedures between functional and industrial design engineers, the 3D virtual verification and validation of the assembly processes, and the automation of extracting documentation, in several formats (paper, electronic, augmented reality), needed to execute the assembly processes at the shop floor.

Modeling Visually Guided Hand Reach for Digital Human Models

Digital Human Models (DHM) are used in digital mockups to identify human factor problems in design and assembly. Present applications are mostly limited to the posture, biomechanics, reach and simple visibility analysis and they are mostly developed for independent simulations that are mostly hand crafted by designers. Our aim is to develop natural simulations using vision as a feedback agent for performing any postural simulations similar to humans. In this paper, the work presented is limited to demonstrating active vision based feedback for a typical hand reach task without using inverse kinematics. The proposed concept takes into account of previously developed vision and hand modules and describes an integration methodology such that both modules can work in tandem providing feedback and feed forward mechanisms. The scheme primarily utilizes vision module that acts similar to human eyes by providing spatial information about hand and object in workspace. Similar to retinal projection, the workspace object and the model of DHM hand is geometrically projected over the grid and the relative positions are computed in terms of grid-cells. The computed relative positions are used to compute a vector direction that is provided as a feedback to hand for guiding it towards object. The hand module independently is capable of natural grasping and visual feedback is used for motion guidance. The implementation shown in this paper is limited to monocular vision and two-dimensional hand movement as a proof of concept. This scheme is used to demonstrate a scenario where DHM is successfully able guide the hand and point it to a given object. The presented model finally shows vision as a guiding agent for hand reach simulations. It can be used for planning and placement of workspace objects to enhance human task performance.

A New Hybrid Modeling Method for Performance Digital Mock-Up of Hypersonic Vehicle

A New Hybrid Modeling Method for Performance Digital Mock-Up of Hypersonic Vehicle

A New Hybrid Modeling Method for Performance Digital Mock-Up of Hypersonic Vehicle

For the characteristics that a hypersonic vehicle has a large span of flight height and flight Mach number, and complicated flight environment, the model of which is highly nonlinear, unstable and multivariablecoupled, where using a single modelling approach is often difficult to achieve high modeling accuracy, hybrid modeling method is proposed to design its performance digital mock-up. The performance digital mock-up hybrid model are designed by using fuzzy set theory, neural networks and system identification method based on combination of the three fuzzy neural network identification method and technology. The simulation results show that high modeling accuracy of this modeling method is generally conventional neural network or fuzzy identification incomparable.

쾌속조형기에 의한 기어식 주유장치의 개발

An automatic grease lubricator provides an adequate amount of fresh grease constantly to any type of rotating machine to minimize friction heat and reduce friction loss. This study seeks to develop an automatic grease lubricator by means of rapid prototyping with a gear-driven mechanism and a controlled operation time. The ultimate design is to lubricate an adequate amount of grease by a simple dip-switch clicking mechanism according to an advanced set cycle. The backlash of the gear was minimized to increase the power, and to increase the power of the mechanism, the binding frequency and the thickness of the coil were changed. To control the rotation cycles of the main shaft according to certain set numbers, different resistances and chips were used in the design of the circuit which controls the electrical signals via a pulse. A digital mock-up was analyzed and the rapid prototyping (RP) trial products were tested with a PCB circuit and grease. An evaluation of the outlet capacity of RP trial products was conducted, as the friction caused by the outlet on the wall surface was an important factor in the operation of the equipment. Finally, a finishing process was applied to decrease the roughness of a surface to a comparable level to test the performance of the product.

Development of a gap searching program for automotive body assemblies based on a decomposition model representation

Automobiles, aircraft, and ships require tremendously many parts to be assembled. For developing such large assemblies, most companies accelerate the design process by having many design engineers in different functional or sectional design groups working concurrently. However, interferences and gaps can be found when the parts and sub-assemblies of different design groups are to be assembled. These error cause design changes and additional repair processes, resulting in an unexpected increase in costs and time delays. While the interference problem has been resolved by digital mockup and concurrent engineering methodology, many cases of the gap problem in the automotive industry have been covered by temporary treatments when the gaps are small enough to be filled with sealants. This kind of fast fix can cause leakage into the engine chamber and passenger cabin when the gap size is too big for filling or when the sealant gets old, which can turn fatal. With this research, we have developed a program to automatically find gaps between the parts of an assembly so that design engineers can correct their designs before the manufacturing stage begins. By using the method of decomposition model representation, the program can visualize gaps between complex car body parts as well as estimate their volumetric information. It can also automatically define the boundary between a gap and the exterior space. Although we have reviewed the benefits of the program by applying it to car development, it can also be applied to aircraft and ship designs comprising several parts.

Rapid Simulation of Translucent Material with Contrast-Reversing Rendering

We present a rendering method to reproduce translucent appearances in real-time. Since the translucency is caused by complicated light behavior such as scattering and absorption, reproducing translucent material requires computationally expensive cost. Due to its computational cost, it is difficult to apply the digital mock-up with the computer graphics for the purpose of cost reduction and acceleration of developing products. In order to reproduce the translucent appearance rapidly, we focus on the contrast-reversing image processing. We embed this simple image processing method to the reflection model. Our proposed method can reproduce in real-time with almost the same appearance compared to commercial rendering software.

Research on Hard Rock Tunnel Boring Machine Based on Digital Mockup

A digital mockup of hard rock tunnel boring machine was built in order to study the design method of these large equipments. Technology of digital mockup is introduced and the application background and practical requirement of tunnel boring machine has been discussed in this paper. The kinematics model and FEM model were built based on this digital mockup. The results of simulation experiment can be used to provide pre-feasibility validation and optimization of the equipment.

Research of the Technology and Application of Process Digital Mock-Up for Spacecraft Assembly Based on the MBD

After representing the situation of the spacecraft assembly and the concept of Model Based Definition (MBD), the paper describes the method and principle of Assembly Digital Mock-up (ADMU), which achieved the transition of Engineering Bill of Material (EBOM) to Process Bill of Material (PBOM). With reconstructing EBOM and fulfilling structured Product Attribute, the paper gains the ADMU, which is the data source of spacecraft assembly process design based on 3D models.

Conceptual design and RCS property research of three-surface strike fighter

This paper mainly focuses on the conceptual design and stealth performance of the three-surface military aircraft. A threedimensional (3-D) digital mock-up of the three-surface strike fighter with stealth feature was designed and the schemes of carrying missiles were analyzed in CATIA. Based on physical optics principle and the Method of Equivalent Currents (MEC), a numerical simulation of the RCS feature of the aircraft was carried out with RCSPlus which is a software designed by Beihang University. The paper contributes to the RCS feature analysis of the whole plane and different parts on X-band, S-band and UHF-band and a comparison of RCS feature to Su-37 and T-50 military aircraft is drawn. On X-band, the pitch angle of the incident wave was 0°, and the result shows: (1) Compared with Su-37 aircraft, the forward scattering RCS of the three-surface strike aircraft was reduced to 14.9%, the side scattering RCS to 9.6% and the back scattering RCS to 40.2%. (2) Compared with T-50 aircraft, the forward scattering RCS was reduced to 38.61%, and the side scattering RCS to 67.26%. This paper should be useful for researchers in conceptual design and stealth technology of the military aircraft.

Accessibility Evaluation in Aircraft Cabin Based on Virtual Reality

With the rapid development of the air transport industry, more attention is paid to interior ergonomics analysis which directly affects the time and cost spent during design. To provide a quick and human-in-loop accessibility way to evaluate accessibility in aircraft cabin, a new method based on virtual reality is proposed. In this method, the digital mock-up model is converted to other format which is need to build a virtual environment first, then virtual environment is built and a virtual hand is driven through tracking hand’s position by A.R.T(Advanced Realtime Tracking ) system to carry on accessibility evaluation in the virtual environment. Based on above-mentioned method the aircraft cabin accessibility evaluation system is designed and realized, which is verified by one case of a certain aircraft cabin. The result shows this method is simple and useful, offering a new way for accessibility evaluation in aircraft cabin.

Computer-Aided Usability Evaluation of In-Vehicle Infotainment Systems

This paper reports the development of a computer-aided engineering (CAE) software for human machine interface (HMI) designers to predict and benchmark the usability of in-vehicle infotainment systems. At the front end of the software a graphic user interface (GUI) was developed that allows HMI designers to create digital mockups of designs and setup the tasks for simulation. At the back end a digital driver was created for simulating the driver cognition and performance based on the cognitive architecture of QN-MHP (Queuing Network-Model Human Processor). The software is able to simulate a driver performing in-vehicle secondary tasks (e.g., tuning radios) while steering a vehicle, make quantitative predictions of the driver’s task performance and workload. To validate the software outputs, an experiment was conducted on a driving simulator with two typical in-vehicle infotainment systems (a physical panel and a touch screen), and a radio tuning task was used as a test case. The results show that the software is able to generate task performance and workload estimates that are similar to the empirical data from human participants.

Drop Test Simulation for An Aircraft Landing Gear Via Multi-Body Approach

Abstract This work deals with the effectiveness of a multi-body approach for the study of the dynamic behavior of a fixed landing gear, especially the research project concerns the drop tests of the AP.68 TP-300 aircraft. First, the Digital Mock-up of the of landing gear system in a C.A.D. software has been created, then the experimental structural stiffness of the leaf spring has been validated using the FEM tools MSC. Patran/Nastran. Finally, the entire model has been imported in MSC.ADAMS environment and, according to the certifying regulations, several multi-body simulations have been performed varying the heights of fall and the weights of the system. The results have shown a good correlation between numerical and experimental tests, thus demonstrating the potential of a multi-body approach. Future development of the present activity will probably be an application of the methodology, herein validated, to other cases for a more extensive validation of its predictive power and development of virtual certification procedures.

Methodology to develop a geometric modeling process according to collaborative constraints

A product design goes through a Digital Mock-Up which is based on the product geometric model. This latter has an important role in the design project whose exploitation mainly depends on how it has been established (DELPHI Automotive Systems, Delphi met á plat ses arborescences, CADReport no. 192, février, 2004). Furthermore, the growing competitive context hardly encourages firms to implement new working methods like collaborative engineering. However, its implementation in combination with product geometric data generates many problems in terms of project and data management. For this purpose, this article proposes a methodological solution to the problem at hand. Moreover the problem gets complicated as the project progresses. As a result, the detailed design phase becomes critical particularly in the face of this problem. Therefore, the current article focuses on this phase of the product design process through an example.