Verification Of Simulation Models Research Articles

Examples of dynamic test procedures for steel fibre reinforced concrete

Abstract The aim of this work is to present some examples of experimental tests, which can be usefull for characterizing the resistance to failure of special steel fibre reinforced concrete – SFRC, intended especially for security use in the framework of ballistic and explosion protection. The first type of the tests was the strain gauge - based characterization of the dynamic response of the SFRC concrete block under ballistic loading. The tests were aimed at measuring the deformation response of a concrete specimen of 500 x 500 x 105 mm in dimensions upon the impact of a projectile. The tests were used to support the development and verification of numerical simulation models. For numerical simulations 3D models of individual projectiles were developed. Four T-type strain gauges were glued according to the geometric scheme on the opposite side of a specimen, i.e. on the side behind the impact of the projectile, and they measured the deflection of the plate after the impact of the projectile. The strain response records obtained from the strain gauges were subsequently used for numerical analyses by the use of the LS-DYNA software. The average maximum deflection of the plate at the impact of the projectile was characterized by the strain 400 µm/m. The second type of the tests was concerned with the method of measuring the quasi-dynamic tensile strength of special concrete specimens using an instrumented Charpy tester. The results compare both the breaking energy and the maximum force achieved for hobby concrete (HB) and hobby concrete with wires (HBD) specimens. These were pilot tests to develop the most suitable testing method. For the HB and HBD specimens the maximum force in the tests was found to be 55 N vs. 600 N, and the breaking energy to be 0.4 J vs. 1.3 J.

FEATURES OF BEHAVIOR AND CALCULATION OF DOWEL TIMBER JOINTS WITH SLOTTED-IN PLATES ACCORDING TO EC5

The paper presents an overview of theoretical and experimental studies of connections of timber structures with steel dowel with steel slitted-in plates. The correct choice of the type of connections allows you to significantly influence the total cost of the structure due to the formation of thestructural and assembly scheme of the structure (minimization of the number of nodal and assembly connections), optimal unification of connections isan additional argument for creating an economical and competitive solution. For the analysis of the dowel connection, it is taken into account that theforce is transmitted due to the bending and shear resistance of the fastening element, as well as crumpling in the connected timber elements. The limitstates of the dowel joint are considered loss of strength due to crumpling and splitting of the wood of the hole wall, as well as due to bending of the nailin the nail socket. The works considered in the review provide extensive factual material on the strength of connections depending on the geometricand physical parameters of its components, as well as the stiffness of the connection, which is currently the subject of active attention of researchers. Attention is paid to the need to study the operation of nodes under the action of a moment during group operation of the connection. The analysis of numerous experiments makes it possible to check the reliability of the current design rules and norms of EC5 and the design norms of DBN В.2.6-161:2017 implemented to them, and also revealed the shortcomings and limits of the application of the design rules for this type. connections The results of numerical and experimental studies are the basis for improvingthe structural solutions of the joints of wooden elements and allowed to accumulate significant factual material for the verification of numerical simulation models.

Seismic behavior of precast columns with unbonded prestressed tendons and energy-dissipating bars: physical and numerical investigations

The study of the strength and failure modes of construction components has become increasingly important with the advent of industrialized construction. Recently, because of the need to promote the survivability of both structures and persons, it has encompassed failure modes associated with seismic threats. This study reports the seismic behavior of precast segmented columns designed with both unbonded prestressed tendons (UPTs) and energy-dissipating (ED) bars. A physical specimen was subjected to a quasi-static cyclic test; this permitted the evaluation of the damage mode and behavior of the energy dissipation mechanism, and permitted the establishment and verification of a fiber beam element simulation model. The model was then used to evaluate the effects of the variation of the design parameters on the behavior of precast assembled columns. The test specimen exhibited stable energy dissipation and a pinching effect during cyclic loading. An analysis using the fiber beam element model with varying design parameters revealed that high-strength concrete could mitigate the concrete damage and residual deformation after an earthquake, and that the concrete strength and steel bar strength should be matched when enhancing the seismic resilience of precast columns with high-strength steel bars. It was determined that increasing the prestress mechanism, namely the ratio of the UPTs, could greatly improve the residual deformation, while the ratio of ED bars is the key factor in enhancing the energy dissipation capacity of the precast columns. Suitable ratios of UPTs and ED bars are the keys to ensuring stable energy dissipation and low residual drifts. Moreover, an increased axial load ratio and prestress level are able to restrain the joint opening and improve the bearing capacity of the precast columns; however, an excessive axial load or prestressing force would result in the rapid degeneration of the carrying capacity and larger residual displacements.

Field experiences and lessons learned from applying participatory system dynamics modelling to sustainable water and agri-food systems

Achieving the objectives of sustainable development in water and agri-food systems requires the utilisation of decision-support tools in stakeholder-driven processes to construct and simulate various scenarios and evaluate the outcomes of associated policy interventions. While it is common practice to involve stakeholders in participatory modelling processes, their comprehensive documentation and the lessons learned remain scarce. In this paper, we share our experience of engaging stakeholders throughout the entire system dynamics modelling process. We draw on two projects implemented in the Volta River Basin, West Africa, to understand the dynamics of water and agri-food systems under changing environmental and socioeconomic conditions. We outline eight key insights and lessons as practical guides derived from each stage of the participatory modelling process, including the pre-workshop stage, problem definition, model conceptualization, simulation model formulation, model testing and verification, and policy design and evaluation. Our findings demonstrate that stakeholders can actively contribute to all phases of the system dynamics modelling process, including parameter estimation, sensitivity analysis, and numerical simulation experiments. However, we encountered notable challenges, including the time-intensive nature of the process, the struggle to reach a consensus on the modelled problem, and the difficulty of translating the conceptual model into a simulation model using stock and flow diagrams – all of which were addressed through a structured facilitation process. While the projects were anchored in the specific context of West Africa, the key lessons and insights highlighted have broader significance, particularly for researchers employing PSDM in regions characterised by multifaceted human-environmental systems and where stakeholder involvement is crucial for holistic understanding and effective policy interventions. This paper contributes practical guidance for future efforts with participatory modelling, particularly in regions worldwide grappling with sustainable development challenges in water and agri-food systems, and where stakeholder involvement is crucial for holistic understanding of the multiple challenges and for designing effective policy interventions.

Verification and validation of software process simulation models: A systematic mapping study

AbstractSoftware process simulation models (SPSMs) that are based on descriptive process models offer the executability that can demonstrate dynamic changes of software processes over time. Verification and validation (V&V) is critical in SPSMs for guaranteeing the quality and reliability of models. V&V of dynamic software process models is more complex and challenging than for static software process models. This work systematically summarizes and maps V&V studies in SPSM to provide guidelines for future research and practice. Specifically, this study aims at identifying the focus of research on V&V, the methods used for V&V, and how to implement V&V of SPSMs in software engineering research. We conducted a systematic mapping study on studies of SPSMs that report on their V&V activities. Under the guidance of a V&V meta‐model for SPSMs, we study four research questions about V&V process. We identified 107 primary studies from a pool of 313 papers on SPSMs until 2021. There are two main results of our study. The first one presents the relationship between quality aspects of SPSMs and the V&V methods to assure them. The second result reveals the relationships among the modeling process, three modeling steps, five quality aspects, and 10 V&V methods. Generally, researchers do not pay sufficient attention to V&V, as 65.8% ( ) failed to mention or elaborate on their V&V process. We systematically summarize and map the state‐of‐the‐art V&V research in software process modeling field to support modelers' practice and improve their V&V process.

Validation of inductively coupled plasma simulation model by laser Thomson scattering experiment

To comprehensively study the physical properties of inductively coupled plasma (ICP), a finite element method (FEM) simulation model of ICP is developed using the well-established COMSOL software. To benchmark the validation of the FEM model, two key physical parameters, the electron density and the electron temperature of the ICP plasma, are precisely measured by the state-of-the-art laser Thomson scattering diagnostic approach. For low-pressure plasma such as ICP, the local pressure in the generator tube is difficult to measure directly. The local gas pressure in the ICP tube has been calibrated by comparing the experimental and simulation results of the maximum electron density. And on this basis, the electron density and electron temperature of ICP under the same gas pressure and absorbed power have been compared by experiments and simulations. The good agreement between the experimental and simulation data of these two key physical parameters fully verifies the validity of the ICP FEM simulation model. The experimental verification of the ICP FEM simulation model lays a foundation for further study of the distribution of various physical quantities and their variation with pressure and absorption power, which is beneficial for improving the level of ICP-related processes.

A Continuous Process for Validation, Verification, and Accreditation of Simulation Models

A simulation model, and more generically, a model, is founded on its assumptions. Assurance of the model’s correctness and correct use is needed to achieve accreditation. Often the exercise of working with a specific code misunderstands the overall process, focusing the resources on the model coding and forgetting the needed resources to ensure the validation of every step of the model definition and coding. The goal of this work is to present a methodology to help in the definition and use of the assumptions in the modeling process. To do so, we present a process to conduct a simulation project, an assumptions taxonomy, and a method that simplifies working with those assumptions. We propose to extend the traditional Validation, Verification, and Accreditation processes to a process composed of eight Validation, Verification, and Accreditation phases that cover the overall life cycle of a model. Although this paper is focused on a simulation model, we can extend the proposed method to a more general modeling approach.

A study of repeatability of hot smoke test in a subway station

Hot smoke test is a key method for fire studies in metro systems. But most hot smoke test scenarios are conducted only once, which ignores the experiment uncertainties and errors. To quantify the uncertainty and repeatability of hot smoke tests in subway stations, seven experiments are repeated on a station platform. 120 thermistors are deployed among the platform to acquire the temperature curves in the experimental area. The concept of statistical analysis and functional analysis is adopted to study the error and turbulence caused by random effects. The results indicate that: (1) According to the fluctuation properties, the experiment area is divided into fire plume area and ceiling jet area. The data uncertainty of the fire plume area is significantly higher than the ceiling jet area. (2) The repeatability of temperature data in the fire plume area is poor. The difference between single experiment curve and average curve might reach 23%–24%. (3) The repeatability of the data in the ceiling jet area is much better with a deviation smaller than 7.8%. The validated experiment data presented in this work could be used for simulation model verification. The repeatability analysis method presented is applicable for other fire studies.

A Random Matrix Model of Business Administration Based on Business Process Orientation in Market Economic Environment

The optimization of business management strategy is a research hotspot in the field of resource processing under the market economy environment. Based on the theory of business process orientation, this paper constructs a reactive power optimization method of random matrix for business management and verifies the correctness and effectiveness of the method through an example. The random matrix construction method of enterprise management network and the feature extraction method that can reflect the operating state of the system are optimized, and the conflict problem in the process of enterprise management resource competition is solved. In the process of OpenDSS/Matlab cosimulation, the business management network state data and random matrix index data are processed by means of statistical modeling and feature extraction, and the random Petri net technology is used to construct a continuous time random matrix. The experimental results show that, combined with the verification of the business management network simulation model of the transformed IEEE-37 node, the traditional optimization method takes 96.63 s, while the business process-oriented scene matching method takes 1.32 s, which shows that the business process-oriented method constructed in this paper takes 96.63 s. The business management random matrix has obvious advantages in optimizing the operation speed, which verifies the accuracy, feasibility, and rapidity of the method and effectively improves the performance of the system.

Research on simulation model validation based on probability relational analysis

The most basic and direct method for simulation model validation is to compare the consistency of missile flight data and simulation data under the same input conditions. However, the existing dynamic data consistency analysis methods are mainly suitable for the case between 1-D missile flight data and 1-D simulation data, and do not conform to the consistency test of single sample flight data and multi-sample simulation data in equipment qualification/finalization test. To solve this problem, a simulation model validation method based on probabilistic relational analysis is proposed. The consistency of output data is measured from the two scales of probability relational coefficient and probability relational degree. The probability relational coefficient is determined by calculating the cumulative distribution probability value of real missile flight samples in the distribution function constructed by simulation data. The probability correlation degree is calculated by judging whether the probability relational coefficient satisfies the uniform distribution of[0 1]. The consistency analysis problem of a kind of dynamic data association is solved accordingly. The correlation theorem that the probability relational degree must satisfy and its property are proved. Meanwhile the operation steps of simulation model verification based on probability correlation analysis are given. This method can process all multi-dimensional simulation data at the same time, and integrate the random factors in the test process, so it can make full use of the test information under the condition of small sample flight test, and improve precision and the reliability of simulation model verification. The rationality and validity of this method are further verified by numerical tests and application examples.

A new high-precision star map simulation model and experimental verification

In order to meet the ground test requirements of star sensors and solve the problem of the non-linearity between the apparent magnitude and the total grey value of the stars encountered in actual measurement, the colour index of stars and the theory of blackbody radiation are introduced to modify the simulation model which only used apparent magnitude formerly. In addition, simulation accuracy evaluation parameters are established based on the characteristics of star points. Finally, practical star observation experiments are carried out with a KAI-4021 detector as an example. Through the comparison between the measured and simulated star maps, the average grey-scale error is less than 12%, which is typically smaller than that of AGS model, and the error is reduced by 5% to 15%. The experimental results show that the proposed star map simulation method has higher accuracy and can provide star maps for star sensor ground tests. https://doi.org/10.1364/99.099999

SYSTEM DYNAMICS FOR SIMULATION MODEL OF MATERIAL COST IN WATER RECOURCES PROJECT

Project cost is one of the constraints in the achievement of a construction project. Limitation on projects financing require more realistic and efficient cost analysis in preparation of project. Due to changes in projects planning over time, it is usually difficult to predict the future project cost. So, we need an integrated system and give an efficiency for the planner. Project cost consists of cost components which is there are an interrelationship each other’s and influencing the overall cost of the project. The approach using system dynamic is one of the best solutions to identify the causal relationship between cost components by using software tools Ventana Simulation (Vensim) to facilitate the identification of causal relationship (causatic diagram) and mathematical equations between variables in stock flow diagram. The results of system dynamic approach show that the simulation model can be used to predict/ estimate the project’s cost in the coming years. Verification and validation of simulation model is eligible based on the value of means comparison, E1 = 0.32% < 5% and % error variance, E2 = 3.19% < 30% so the developed model can be done scenarios for changes that occur on the system according to the user needs.

Cooling Panel with Integrated PCM Layer: A Verified Simulation Study

The focus of this research paper is to develop a verified simulation model for a cooling panel with integrated phase-change materials (PCMs)—a stainless steel panel filled with PCM and integrated hydronic piping circuit. This solution is targeted for passive cooling of residential buildings in Baltic Sea region that experience overheating for most of the year due to highly insulated building envelopes and extensive glazing—a phenomena for nearly zero energy buildings (NZEBs). This approach aims to maintain comfortable indoor temperature all year round by passive means—free-cooling, adiabatic (evaporative) cooling or limited mechanical cooling. The simulations are performed with IDA ICE 4.8 and the measurements for simulation model verification are collected from a test chamber. The results show that reasonable agreement can be reached for simulated and experimentally measured data.

The General Principles of the Transportation Simulation Model Development and Validation

Transportation simulation model development allows simulating traveller’s decisions, evaluating various transportation management strategies and complex solutions. The aim of the paper is to set the general principles of the transportation simulation model development and validation. The paper contains the overview of the transportation simulation models types with the examples from the conducted projects for the Riga city. The basic steps of the simulation model development procedure: initial data preparation and analysis, transportation model development and simulation, scenarios planning and evaluation, and simulation models outcomes evaluation are considered. Simulation model verification, validation and calibration definitions are given. The basic checks for the transportation macroscopic and microscopic simulation model validation are listed. A summary of the transportation simulation model validation and calibration methods and parameters is given.

Simplifying the Verification of Simulation Models through Petri Net to FlexSim Mapping

Simplifying the encoding of a simulation conceptual model representation reduces the number of errors that will be detected in the verification phase. In this paper, we present a mapping between Petri nets, a well-known formalism, and FlexSim, a well-known simulation tool. The proposal is illustrated through an example of how a model specified in a Petri net can be encoded easily, reducing the time needed to understand and verify the model. In the proposed methodology, the mapping must be defined at the initial stage of the encoding, starting from (in this case) a Petri net conceptual model, and ending at the encoding tool (FlexSim in this case). The main advantages of the proposed methodology are discussed.

Метод структурно-графического анализа и верификации интеллектуальной имитационной модели

Метод структурно-графического анализа и верификации интеллектуальной имитационной модели

Electric vehicle energy consumption estimation for a fleet management system

Accurate estimation of vehicles’ energy consumption is a demanding task. It might not be so critical for conventional vehicles because of their high travel range; however, this is something important for electric vehicles (EVs). On the other hand, EVs with less energy on board need more accurate energy management systems. This study focuses on the development of an energy consumption estimation model to be used in an EV fleet management system (FMS). The proposed estimator consists of a vehicle model, a driver model, and terrain models. It is demonstrated that a combination of these three parts can provide an accurate estimation of EV energy consumption on a particular route. As part of this study, a commercially available passenger car is modeled using MATLAB/Simulink. A number of specific routes are selected for EV road testing to be driven for simulation model verification. In the second part of this study, the impact of energy consumption estimation accuracy is investigated at a larger scale for a fleet of EVs. It is quantitatively demonstrated how much sensitive is the performance of a FMS to the accuracy of the energy estimator. Simulation results have shown that the total energy consumption of an EV fleet is decreased significantly by improving the estimation accuracy. It is also demonstrated how the uncertainties in EV energy consumption estimation limit the overall performance of a FMS.

Phase Modulated Radio-Over-Fiber for Efficient 5G Fronthaul Uplink

Analog radio-over-fiber technology is gaining interest as a potential candidate for radio signal transport over the future fronthaul section of the 5th generation (and beyond) radio access network. In this paper, we propose a radio-over-fiber fronthaul with intensity modulation in the downlink and phase modulation with interferometric detection in the uplink, for simplified and power efficient remote units. We conduct an experimental investigation and verification of theoretical and simulation models of the performance of the phase-modulated uplink and demonstrate the ability of such an architecture to transport single-channel and multi-channel 5G-type radio waveforms. Experimentally verified data rates of 4.3 Gbps and simulation-based predictions, using a well matched-to-measurements model of the uplink, of 12.4 Gbps are presented, with error-vector magnitude performance well within relevant standard specifications for 64-QAM.

Molecular simulation of CH4 adsorption behavior in slit nanopores: Verification of simulation methods and models

AbstractThe aim of this study is to select an appropriate method for CH4 adsorption in organic nanopores for shale‐gas development. Molecular dynamics (MD) and grand canonical Monte Carlo (GCMC) simulations were performed. Three comparison studies were included: (i) comparison of the adsorption behavior in kerogen nanopores using different schemes for dispersion correction, (ii) comparison of the adsorption behavior in graphite nanopores using MD and GCMC simulations, and (iii) comparison of the adsorption behavior in kerogen and graphite nanopores using MD simulations. The result was reliable when using a particle‐mesh Ewald scheme or a cut‐off ≥1.5 nm without dispersion correction. The simulation results were essentially identical for the MD and GCMC simulations. The free‐gas CH4 density inside the nanopores started to deviate from the bulk density at ~2 nm for the graphite model and at ~7–10 nm for the kerogen model, whereas the total CH4 density deviates from the bulk density at ~20 nm.

Verification of a low fidelity fast simulation framework through RANS simulations

Verification and validation of simulation models are critical steps in engineering. This paper aims at verifying the suitability of reduced order aerodynamic models used in an aeroservoelastic framework designed to analyze the flight dynamics of flexible aircraft, known as the Cranfield Accelerated Aircraft Loads Model. This framework is designed for rapid assessment of aircraft configurations at the conceptual design stage. Therefore, it utilizes or relies on methods that are of relatively low fidelity for high computational speeds, such as modified strip theory coupled with Leishmann–Beddoes unsteady aerodynamic model. Hence, verification against higher order methods is required. Although low fidelity models are widely used for conceptual design and loads assessments, the open literature still lacks a comparison against higher fidelity models. This work focuses on steady-trimmed flight conditions and investigates the effect of aerodynamic wing deformation under such loads on aerodynamic performance. Key limitations of the reduced order models used, namely fuselage and interference effects, are discussed. The reasons for the overall agreement between the two approaches are also outlined.