Virtual Bench Research Articles

Determining the Mechanical Properties of Super-Elastic Nitinol Bone Staples Through an Integrated Experimental and Computational Calibration Approach.

Super-elastic bone staples have emerged as a safe and effective alternative for internal fixation. Nevertheless, several biomechanical aspects of super-elastic staples are still unclear and require further exploration. Within this context, this study presents a combined experimental and computational approach to investigate the mechanical characteristics of super-elastic staples. Two commercially available staples with distinct geometry, characterized by two and four legs, respectively, were examined. Experimental four-point bending tests were conducted to evaluate staple performance in terms of generated forces. Subsequently, a finite element-based calibration procedure was developed to capture the unique super-elastic behavior of the staple materials. Finally, a virtual bench testing framework was implemented to separate the effect of geometry from that of the material characteristics on the mechanical properties of the devices, including generated force, strain distribution, and fatigue behavior. The experimental tests indicated differences in the force vs. displacement curves between staples. The material calibration procedure revealed marked differences in the super-elastic properties of the materials employed in staple 1 and staple 2. The results obtained from the virtual bench testing framework have showed that both geometric features and material characteristics had a substantial impact on the mechanical properties of the device, especially on the generated force, whereas their effect on strain distribution and fatigue behavior was comparatively less pronounced. To conclude, this study advances the biomechanical understanding of Nitinol super-elastic staples by separately investigating the impact of geometry and material characteristics on the mechanical properties of two commercially available devices.

The method of virtual bench tests conducting to analyze the vehicle technical characteristics compatibility to detect and prevent the risk of resonant phenomena in the sprung cab

BACKGROUND: A relevant issue when designing vehicles with multiple levels of suspension systems is collaborative operation of these systems, which ensures the required vehicle dynamics and smoothness parameters, as well as the absence of risk for the occurrence of resonance phenomena. The vehicle cab is a dynamic system with 6 degrees of freedom, so its oscillatory motions have a complex spatial character with the oscillation energies overflow from one direction to another. The solving of problems of the sprung cab dynamics should be conducted in a spatial nonlinear formulation, which makes it possible to take into account the phenomena of redistribution of oscillation energy between the directions of space. This approach can be put into operation with simulation modeling methods through creating a spatial virtual rig of the cab with a suspension system and modeling its dynamics with the application of appropriate external inputs.
 AIM: Development of the method of using virtual tests to analyze the compatibility of technical characteristics of the cab suspension system, the frame system and the primary vehicle suspension systems to detect and prevent the risk of resonant phenomena in the cab.
 METHODS: Building a virtual test rig of a vehicle cab as a multibody dynamics system of connected bodies in space, mounted at the movable vehicle frame with spring-dampers. Virtual tests are conducted by simulation modeling methods according to the method for analyzing nonlinear phenomena when spatial resonances occur in the secondary suspension system of a vehicle cab.
 RESULTS: The method of vehicle cab virtual tests conducting for analyzing oscillatory processes occurring in the cab, including resonances, using a virtual test rig in a multibody dyamics software package.
 CONCLUSION: The developed method ensures an ability to take measures to detect and prevent the risk of spatial resonance phenomena in the vehicle cab at all stages of the components design and the cab suspension systems study.

ВИРТУАЛЬНЫЙ СТЕНД ДЛЯ РЕАЛИЗАЦИИ ПРОЦЕДУРЫ ПОВЕРКИ РАСХОДОМЕРОВ

Development of a virtual bench for verification of flowmeters based on the UNITY platform, taking into account the actual operating conditions of the verification facility

Key Technologies of Physical and Virtual Test Rig for Railway Freight Car body

On the one hand, considering that the traditional fatigue method of railway freight cars is based on damage as a parameter, the influence of stress waveform cannot be considered. On the other hand, physical experiments have the characteristics of lag, long period, and high cost. The full-scale physical test and virtual test of car body are carried out. First of all, the data processing method of small deletion and the inverse problem load acquisition method based on data to data are proposed. Secondly, the dynamic stress calculation method with the bench as the boundary is proposed. Finally, taking the obtained load as the input of the physical and virtual bench, a new fatigue test method for simulating the running attitude of the car body line is completed. The acceleration RMS error of the C70E gondola body is less than 6%, the stress RMS is less than 13%, and the equivalent mileage is 3.125 million highway test results show that the car meets the life requirements of the car body. The inverse problem analysis results of virtual and physical tests are basically consistent, and the study of this method provides a basis for improving the fatigue reliability of freight car bodies.

Организация мониторинга сетевых вторжений на основе свободно распространяемого программного обеспечения

This paper presents the results of preparing a virtual bench for modeling and detecting network attacks using a freely distributed intrusion detection system (IDS). The relevance of the work is related to the growing demand for IDS as sources of information security events for security information and event management (SIEM) systems. A comparative analysis of the most popular freely distributed open-source network IDSs was carried out and the choice of the Zeek system for its use in the project was substantiated. The work uses Zeek network logs, which contain important and structured information about the analyzed network traffic. The laboratory bench was built on the basis of a Linux virtual machine and a Mininet network simulator. A graphical representation of the developed virtual stand is proposed. An experimental study of the effectiveness of an intrusion detection system is demonstrated by simulating a network denial of service attack and further analyzing the received network traffic using IDS tools.

Development of a Virtual Bench for Modeling and Research of a Mobile Robot in Simintech

A virtual bench is designed for students studying simulation, model-oriented design of mechatronic systems and control devices. A review of existing virtual stands is performed. The training starts with simulation of a mobile robot (MR) with a single drive, for example, a transport robot moving along one coordinate, then simulation of MR with differential control moving on a plane, and then simulation of multicopters (quadcopter, hexacopter, octocopter). The virtual simulator consists of a model of MR with a single DC motor drive, MR controller, control panel. The drive model of the mobile robot in the state space is developed. Negative trends in the development of laboratory benches have been revealed: fast obsolescence of laboratory equipment; high cost; small range of equipment. Positive directions of their development have been identified: expansion of software capabilities (high-level languages) allowing to create any applications quickly and easily; appearance and improvement of special software used to create multimedia applications, as well as specialized software intended for design automation (AutoCAD, KOMPAS, Altium Designer, etc.) and mathematical calculations (Matlab, MathCAD, etc.). Software tools include SimInTech, MatLab/Simulink, LabVIEW, procedure-oriented languages VB, Delphi, Java, etc.; problem-oriented languages LISP, C++, C#, etc. In this connection, it is expedient to partially abandon traditional laboratory benches and switch to wider application of simulation modeling and computational experiment methods. Virtual laboratory benches should form the basis of such transition. As a result of simulation, the following parameters of MR model were obtained: MR displacement at 2.5 m, maximum gearbox angular speed 0.2 rad/s, maximum torque on gearbox output shaft 15 N∙m, maximum angular speed of DC motor 30 rad/s. Simulation of MR was performed in SimInTech program.

Development of a virtual bench for the analysis of the physical processes of internal combustion engines

Currently, internal combustion engines face the challenge of reducing fuel consumption and reducing polluting emissions due to their significant impact on the environment. Therefore, it is necessary to use tools that allow us to evaluate the operating characteristics of this type of thermal machines. In the present investigation, the development of a virtual bench was proposed for the analysis of the behavior and performance characteristics of an internal combustion engine for use as a learning tool in higher education students. From the results obtained, it could be demonstrated that the pressure curves of the combustion chamber and the rate of heat release obtained by means of the virtual bench presented a high concordance with the experimental records. The maximum deviation obtained was 5% and 15% for the pressure curve and the heat release rate. Comparing the performance parameters of the brake specific fuel consumption of the engine and energy efficiency, a maximum deviation of 2.96% was shown compared to the real engine. In general, the virtual development bank can describe the behavior of the engine, allowing the characterization of physical phenomena, as well as evaluating the effect of auxiliary technologies such as turbo-compression systems.

NETWORK INTERACTION IN VIRTUALIZED ENVIRONMENTS AND FEATURES OF VIRTUAL STAND DEVELOPMENT

This article describes a virtual bench developed by the authors for studying network interaction in virtualization and containerization environments. The functional diagrams of the two modules of the stand are presented, as well as the exact characteristics of the software and hardware used in the work. The study of network interaction is carried out in a certain complex of proprietary and free software, which distinguishes it from previous studies. To build a virtual stand, the VMWare system was used, with the help of which 2 stand modules were created. The hypothesis of the research is that installed DPDK libraries on hosts and VMs and containers, as well as configuring OvS will increase network performance, which includes bandwidth and latency parameters. Network research is carried out in two modes of operation using the software switch Open vSwitch and DPDK libraries. The results of the study and the authors recommendations are given at the end of the work. Also, the key features of configuring virtual machines, containers and software switch, which are the main objects of research, were described. Further research on the topic involves defining a set of best practices for configuring all components of the network infrastructure (including the number of numa nodes, cpu pinning topology and the amount of huge pages), and making recommendations for choosing the main parameters of VMs and containers.

Experimental determination of compressor map of the DGEN 380 engine compressor using the WESTT CS/BV turbine engine simulator

Currently aviation focuses mainlly on increasing the economy and ecology of engines. Production of NOx, CO2 and SO adversaly impacts the environment. Parallel goal to minimize SFC to achieve both lower: emission and mission costs. The optimization of components is thus very important. One of the ways of optimizing cycle is doing that based on compressor maps. However it is very expensive to plot one since experimental work needs to be done. The aim of this article is to present a methodology of creating compressor map based on ENGINE ANALOGY. There was used the virtual bench WESTT CS/BV for tests to receive pressure ratio and mass flow of DGEN 380 for three different values of flight speed and altitude, while the rotational speed was changed. The construction similarity of CFM 56-5B and APS 3200 gives the opportunity to plotted compressor maps using the engine analogy without the need for an experiment or using the virtual bench.

In silico virtual screening of lead compounds for major antigenic sites in respiratory syncytial virus fusion protein

Human respiratory syncytial virus (RSV) is a leading ubiquitous respiratory pathogen in newborn infants, young children, and the elderly, with no vaccine available to date. The viral fusion glycoprotein (RSV F) plays an essential role in the infection process, and it is a primary target of neutralizing antibodies, making it an attractive site for vaccine development. With this in view, there is a persistent need to identify selective antiviral drugs against RSV, targeting the major antigenic sites on the F protein. We aimed to conduct a robust in silico high-throughput drug screening of one million compounds to explore potential inhibitors that bind the major antigenic site Ø and site II on RSV F protein, which are the main target of neutralizing antibodies (NAb). We utilized the three-dimensional crystallographic structure of both antigenic site Ø on pre-F and antigenic II on post-F to screen for potential anti-RSV inhibitors. A library of one million small compounds was docked to explore lead binders in the major antigenic sites by using virtual lab bench CLC Drug Discovery. We also performed Quantitative Structure-Activity and Relationship (QSAR) for the lead best binders known for their antiviral activity. Among one million tested ligands, seven ligands (PubChem ID: 3714418, 24787350, 49828911, 24802036, 79824892, 49726463, and 3139884) were identified as the best binders to neutralizing epitopes site Ø and four ligands (PubChem ID: 865999, 17505357, 24802036, and 24285058) to neutralizing epitopes site II, respectively. These binders exhibited significant interactions with neutralizing epitopes on RSV F, with an average of six H bonds, docking energy of − 15.43 Kcal·mol−1, and minimum interaction energy of − 7.45 Kcal·mol−1. Using in silico virtual screening, we identified potential RSV inhibitors that bind two major antigenic sites on the RSV F protein. Using structure-based design and combination-based drug therapy, identified molecules could be modified to generate the next generation anti-RSV drugs.

Approaches to testing vehicle passive safety based on a virtual test bench and a digital twin

The article presents the results of the implementation of work in the field of creating virtual test benches for testing vehicle passive safety in the event of an impact. A number of results obtained on the basis of implemented virtual platforms and benches are given. The advanced technologies in the field of creating virtual benches and digital twins are also shown. The illustrations on the problems of testing A-pillars and the vehicle roof, including the cases of a frontal impact are given. Certain considerations are given on the general concept of digital design based on digital twins and virtual test benches. The critical impact on the adequacy of the digital twin and the benches and platforms built on its basis is highlighted. The accuracy and convergence of the mathematical model of the designed product and the physical processes occurring in it, the used numerical methods of computer simulation, finite element models and their optimization is pointed out.

Results of the implementation of work on the creation of virtual test benches for testing the digital twin of the bus

The results of the implementation of work in the field of creating virtual test benches for testing digital twins of products in the automotive industry are presented. The results of the implementation of virtual benches for assessing the water tightness and drainage of bus bodies are specifically considered. The structure of the virtual bench for assessing the sound absorption of materials in the alpha chamber is given. The results of the development of the concept of a virtual test bench for the bus electrical equipment simulation are presented.

Development of virtual benches for testing the digital twin of a vehicle

The article analyzes the approaches to the creation of the concept of a virtual test bench for testing the digital twin of the automotive industry product. Such components of the digital platform as suspension area, power plant, braking and cooling systems are being investigated. The problem of the implementation in the digital twin of such important units as the attachment points of units and assemblies on the vehicle body frame, even surface, driver dummy, the scheme of attachment of body elements, etc is studied. The importance of the implementation of such benches as platforms for assessing the indicators of the vehicle passive safety or as stand for assessing the water tightness of the vehicle body is considered. A number of results that illustrate development areas and success of the authors of the article in these areas are presented. It is shown that the digital platform can be used for certification and rating tests, assessing the comfort and visibility of the driver's cab.

Study of the process overcoming obstacles by tillage tools on a three-dimensional dynamometric virtual stand

The interaction of resiliently fixed tillage tools and obstacles is investigated using computer applications that simulate the dynamics of motion of 3D models, created in CAD. The design of a virtual bench and a dynamometer block, implemented in CAD SolidWorks and an application for modeling the movement dynamics SolidWorks Motion, is described. The virtual stand allows you to simultaneously record all components of the traction resistance vector (RX, RY, RZ). With the help of a virtual stand, the volumetric force characteristics of the process of overcoming a stump by a section of a modular tillage unit were measured. Four types of tillage tools were investigated: plowing disk; cultivating disk; sweep tool; subsoiling tool. In experiments, a 20 cm stump was overcome. Conditional processing depths for tillage tools were set depending on their technological purpose. Two types of interaction were investigated: frontal and maximum lateral displacement. The greatest loads during frontal overcoming of obstacles were experienced by a plow disc tillage tool. At maximum lateral displacement, the subsoiling tool was the most loaded. The results of the experiment showed that all the investigated tillage tools are able to overcome the stump with the parameters used.

Development and research of a virtual test bench for electric impedance tomography channel main components simulation

When developing and determining the principles of construction and algorithms for the operation of electrical impedance tomography devices, it is necessary to verify the adequacy of the adopted circuitry solutions, their technical level and the possibility of practical implementation. To assess the technical capabilities and operating parameters of the device and its components, it is advisable to develop specialized tools for research and adjustment. Considering that the devices for electrical impedance tomography being developed are hardware and software solutions, and their components are complete electronic units that interact with each other, it seems possible to develop an experimental bench. The development of a virtual automated experimental bench for preliminary tests of the main components of the electrical impedance tomography channel is proposed. On the basis of the operating principles of the hardware bench, the principles of building a virtual bench are formulated. The correspondence of the main elements of hardware and virtual benches in terms of their functional purpose is shown. For each of the software components of the virtual bench, input actions and output parameters are determined. A schematic diagram of the analog part of the electrical impedance tomography channel has been developed to test the performance of the virtual bench. Studies have shown that the developed virtual bench is suitable for preliminary testing of all analog components of the channel. The use of the developed virtual bench will allow optimizing the time and material costs for conducting experimental research in the process of developing hardware for technical means of electrical impedance tomography

Finite Element Analysis of Custom Shoulder Implants Provides Accurate Prediction of Initial Stability

Custom reverse shoulder implants represent a valuable solution for patients with large bone defects. Since each implant has unique patient-specific features, finite element (FE) analysis has the potential to guide the design process by virtually comparing the stability of multiple configurations without the need of a mechanical test. The aim of this study was to develop an automated virtual bench test to evaluate the initial stability of custom shoulder implants during the design phase, by simulating a fixation experiment as defined by ASTM F2028-14. Three-dimensional (3D) FE models were generated to simulate the stability test and the predictions were compared to experimental measurements. Good agreement was found between the baseplate displacement measured experimentally and determined from the FE analysis (Spearman’s rank test, p < 0.05, correlation coefficient ρs = 0.81). Interface micromotion analysis predicted good initial fixation (micromotion <150 µm, commonly used as bone ingrowth threshold). In conclusion, the finite element model presented in this study was able to replicate the mechanical condition of a standard test for a custom shoulder implants.

Neural Computing Enhanced Parameter Estimation for Multi-Input and Multi-Output Total Non-Linear Dynamic Models

In this paper, a gradient descent algorithm is proposed for the parameter estimation of multi-input and multi-output (MIMO) total non-linear dynamic models. Firstly, the MIMO total non-linear model is mapped to a non-completely connected feedforward neural network, that is, the parameters of the total non-linear model are mapped to the connection weights of the neural network. Then, based on the minimization of network error, a weight-updating algorithm, that is, an estimation algorithm of model parameters, is proposed with the convergence conditions of a non-completely connected feedforward network. In further determining the variables of the model set, a method of model structure detection is proposed for selecting a group of important items from the whole variable candidate set. In order to verify the usefulness of the parameter identification process, we provide a virtual bench test example for the numerical analysis and user-friendly instructions for potential applications.

Engine Valvetrain Lift Prediction Using a Physic-based Model for The Electronic Control Unit Calibration

The electronic control has an increasingly important role in the evolution of the internal combustion engine (ICE) and the vehicle. Research in the automotive sector, in this historical period, is dictated by three main guidelines: reducing polluting emissions and fuel consumption while maintaining high performance. The Electronic Control Unit (ECU) has made it possible, complicating the engine both in terms of architecture and in terms of strategies, controlling, through simplified functions, physical phenomena in an ever more precise way. The ECU functions are experimentally calibrated, reducing the error between the quantity estimated by the function and the experimental quantity over the entire operating range of the engine, developing extensive experimental campaigns. The calibration process of the ECU functions is one of the longest and most expensive processes in the development of a new vehicle. Some lines of research have been explored to reduce the experimental tests to be carried out on the test bench. The use of neural networks (NN) has proven to be effective, leading to a reduction in experimental tests from 40 to 60%. Another methodology consists in the use of 1D/0D Thermo-fluid dynamic models of the ICE. These models are used as virtual test benches and through them it is possible to carry out the experimental campaigns necessary for the calibration of the control unit functions. At the real test bench, only the few experimental tests necessary for the validation of the model must be carried out. One of the simplifications that is usually made in the 1D/0D ICE models consists in assigning a single intake and exhaust valve lift, without taking into account the effect of the engine speed on the valve lift in early intake valve closure (EIVC) mode for engines equipped with VVA. This phenomenon has a not negligible effect on engine performance, especially at high engine speeds. In the case of engine models equipped with VVA, the valve lift cannot be imposed, since it is unique for each closing angle at each engine speed. Indeed, in order to assign the correct valve lift for a given engine speed and EIVC, numerous experimental tests should be carried out, making vain the beneficial effects of the method. In this work, the authors propose the use of a 0D/1D CFD model of the entire electro-hydraulic valvetrain VVA module, coupled with 1D lumped mass for reproducing the linear displacements of the intake valve, and for simulating the interactions between flow and mechanical systems of the solenoid hydro-mechanical valve. Thus, model simulations allow to predict the valve lift in all the necessary conditions in the experimental campaigns for the calibration of the control unit functions. Starting from geometric valvetrain data, the model has been validated with a parametric analysis of some variables on which there was greater uncertainty, by comparing the valve lift obtained by the model with the experimental ones in certain engine speeds. Subsequently, the authors have obtained the valve lifts in conditions not used for model validation, comparing them with their respective experimental lifts. The model has proven to be sensitive to the effect of the variation of the engine speed, reproducing the valve lift with a low error. In this way it is possible to reduce the experimental effort aimed to the calibration process considering that the virtual experimental campaign has proven to be reliable.

Optimal Site for Proximal Optimization Technique in Complex Coronary Bifurcation Stenting: A Computational Fluid Dynamics Study

Background/purposeThe optimal position of the balloon distal radio-opaque marker during the post optimization technique (POT) remains debated. We analyzed three potential different balloon positions for the final POT in two different two-stenting techniques, to compare the hemodynamic effects in terms of wall shear stress (WSS) in patients with complex left main (LM) coronary bifurcation. Methods/materialsWe reconstructed the patient-specific coronary bifurcation anatomy using the coronary computed tomography angiography (CCTA) data of 8 consecutive patients (6 males, mean age 68.2± 18.6 years) affected by complex LM bifurcation disease. Subsequently a virtual bench test was performed in each patient using two different double stenting techniques represented by the DK and Nano crush using the reconstruction of Orsiro stents (Biotronik IC, Bulack, Switzerland). ResultsA significant reduction in the mean WSS values in all the lesion's sites was observed when the final POT was performed 1 mm distally the carina cut plane in both techniques. Moreover, a significant improvement in the mean WSS values of the entire SB (e.g. LCX) was obtained performing the POT 1 mm distally to the carina cut plane. The proximal POT resulted in larger area of lower WSS values at the carina using both the Nano crush and the DK crush techniques. ConclusionsIn patients with complex LM bifurcation disease the use of a final POT performed 1 mm distally to the carina cut plane might results in more favorable WSS patterns (i.e. higher WSS values) along all stented segments and, especially, along the entire LCX lesions.

Electronic Study Guides for Applied Bachelor’s Degree Programs

The development of electronic study guides (ESG) for Bachelor’s disciplines enables to reduce procurement costs for print library collections. Posting of ESGs on the University Internet resources will provide their accessibility and usability, so the subject is topical. The article analyzes the experience of developing electronic study guides for the disciplines of basic professional bachelor’s degree programs in various universities and reviews the literature on this subject. The main features that distinguish ESG from paper teaching materials are the following: multimedia presentation of information, interactivity, dynamic content. In addition, remote interaction between a teacher and students in forums or video conferences is possible, depending on the format of the ESG. Furthermore, ESG allows one to remotely monitor the completeness and timeliness of the study of certain topics of the discipline, unlike other types of educational and methodological support. The implementation of the ESG makes it possible to maintain control in two forms: internal and external. There are also such criteria for assessing the quality of ESG as: proportion in ensuring the total volume of discipline, proportion in ensuring the self-directed student work, quality of design, the effectiveness of multimedia, adaptability, level of remote access. The result of the analysis was the development of requirements for the ESG design for the discipline «Structure and calculation of engines». This discipline includes the basics of structure and calculation elements and systems of internal combustion engines and the processes occurring in them. In Perm National Research Polytechnic University, according to the curriculum, the discipline is studied for 2 semesters; the labor intensity is 7 credits. Classroom lessons consist of lectures, laboratory and practical classes, additionally, coursework was provided. The difficulty of organizing and maintaining a laboratory in working condition is due to high labor and material costs for fuels and lubricants, electricity, forced-air ventilation, maintenance and repair of internal combustion engines, etc. In this regard, it is relevant to use simulation methods and create virtual laboratory benches to determine the characteristics of the internal combustion engine. These benches may be considered as an alternative to field experiments and stands. As a result of the generalization experience, it was possible to draw up general requirements to the structure and content of the ESG and to provide recommendations on the development of ESGs taking into account the specifics of applied bachelor’s programs.