Dynamic Simulation Software Research Articles

Dynamic Simulation Model of Miniature Tracked Forestry Tractor for Overturning and Rollover Safety Evaluation

This study proposes a method to construct a dynamic simulation model to implement the lateral overturning and backward rollover characteristics of an actual tractor. Based on theoretical analysis, factors affecting these characteristics are identified, which include tractor weight, track width, wheelbase, location of mass center, weight distribution, heights of front and rear axles, and geometric shapes. The location of the mass center of the actual tractor is measured based on the standard test procedure set by the International Organization for Standardization, and the remaining influencing factors are derived through measurements. A three-dimensional (3D) model of the tractor is constructed to reflect all these factors. Additionally, a simulation model utilizing this 3D model is developed using a commercial dynamic simulation software program. The ability of the model to simulate the overturning and rollover characteristics of the actual tractor is verified by comparing the static sidelong falling angle and minimum turning radius with those of the actual tractor. The errors between the characteristics of the actual tractor and those of the 3D model and dynamic simulations are shown to be less than 5%, thus indicating that the proposed method can effectively simulate the overturning and rollover characteristics of the actual tractor.

The Mathematical Model Based on the Parameters of Simulation Results Predicts the Fire Extinguishing Resource Demand of Naval Fires

In recent years, due to the diversity of fire scenes in ports and ships, the problem of fire command is complicated. In the case of power failure, the original command platform and fire extinguishing system will not be able to be used normally, or the fire extinguishing resources carried by the ship when it is on fire cannot be used. In the traditional firefighting ability research, there is no clear measure of firefighting ability, resulting in inaccurate calculation results. By corresponding to the quantity and composition of resources for the study of fire extinguishing capability, the combination of the fire dynamics simulation software PyroSim2020 and a calculation model that converts its resources into the total amount and flow of fire extinguishing agent can be provided. Based on the analytic hierarchy process (AHP), a firefighting demand grade calculation and judgment model was established, which included five factors: fire scale, combustion material characteristics, foam extinguishing agent performance, firefighting object characteristics, and external factors. It concluded that the demand assignment values of each index element were 2, 5, 6, 9, and 10, and further proposed the grade judgment criteria for the calculation results of comprehensive fire demand. Through the quantitative simulation of firefighting demand based on the fire scenario and calculation model test of the consumption prediction of cooperative firefighting equipment, it can also provide a strategic reference for related cooperative fire rescue.

Identifying vehicle characteristic target based on subjective ratings from drivers

In virtual tire development, defining vehicle characteristic target is crucial to achieving the desired vehicle performance with the equipped tires. Vehicle performance is generally evaluated through subjective ratings by skilled drivers following SAE J1441 guidelines, as well as the objective performance metrics obtained via vehicle dynamics analysis. However, due to the scarcity and bias in real-world testing dataset, the vehicle characteristic target cannot be determined definitively. To address this issue, we propose a recommendation system that searches the unexplored vehicle characteristic domains. This suggested method provides virtual subjective ratings to enrich the limited real-world dataset from the skilled drivers. Moreover, we highlight the correlation between subjective and objective data using vehicle and tire dynamics simulation software. Based on this augmented data, we predict the vehicle characteristic target according to the subjective rating requirements. The proposed approach was validated through various experiments involving skilled drivers and various vehicle-tire combinations, showing 91.26% to 96.2% consistency in generated steering parameter domains. Domains of stability parameters show that one fewer domain was generated by a conservative driver compared to more lenient driver, which confirms the robustness of the proposed approach in accommodating individual driver preferences.

Functionality of Bearings in the Shafts of a Vertical-Axis Wind Turbine

The article contains a description of the design solutions proposed by the authors for a hybrid wind turbine bearing, in which the sliding part takes over the load to the turbine shaft after reaching the shaft rotation speed, ensuring hydrodynamic lubrication of the plain bearing and relieving the rolling bearing. This allows for low starting resistance of the power plant and ensures quiet operation during use. Two conceptual solutions of a hybrid bearing were presented, differing in the shape of the plain bearing journal. A mechanism for automatic switching of the load between a rolling and a plain bearing was developed. A solid simulation model of this mechanism was built in the Autodesk Inventor—Dynamic Simulation software Inventor Professional 2023 environment, and its operation was simulated. The results confirmed the usefulness of using this design in shaft-bearing systems of wind turbines with a vertical axis of rotation. Based on the simulation, the speed at which the thrust roller bearing will be released was determined. Technical parameters of a plain bearing with a spherical journal shape were calculated. The height of the lubrication gap and the shaft rotational speed at which the bearing load capacity index reaches a critical value were determined.

A dynamic risk assessment model for evacuation in healthcare facilities during fire scenarios

Evacuation is a critical procedure for safeguarding individuals during a fire incident within a healthcare facility. Assessing the risk associated with the evacuation process is instrumental in enhancing emergency decision-making and developing contingency strategies. Evacuation, a dynamic process, poses challenges in accurate risk evaluation using conventional static quantitative risk assessment (QRA) techniques. This study introduces a dynamic QRA approach to precisely evaluate the evacuation risk to individuals in healthcare settings during a fire. The dynamic event tree methodology is initially utilized to determine the evolving probabilities of various fire scenarios, considering the equipment failure and repair rates. Subsequently, data on fire products and the evacuation of individuals under different fire scenarios are gathered through simulations conducted with Fire Dynamics Simulator (FDS) and Pathfinder software. In addition, this research proposes a dynamic incapacitation model to calculate the consequences of fire, incorporating changes in individuals' locations and the fire products surrounding them during evacuation to accurately estimate the casualty risk. Lastly, the dynamic scenario probability was integrated with the average incapacitation probability for all individuals, introducing the concept of a fire evacuation safety time window to comprehensively assess hospital fire evacuation risk. The findings revealed that the dynamic quantitative risk analysis (DQRA) approach more effectively captures the influence of fire products on the evacuation risk compared to static methods. Specifically, the peak incapacitation probability in a hospital fire reached 0.85, with firefighting equipment, especially the sprinkler system, reducing this risk by over 97% and decreasing evacuation time by 45%. In addition, the risk of fire evacuation in hospitals reaches a critical threshold in the fourth year, enhancing the repair rate of the firefighting system postpones the risk's escalation to a critical threshold until the fourteenth year.

Numerical Analysis of SiC and UHMWPE Composite Ballistic Plates against 0.5 Caliber BMG Projectile

The aim of this study was to determine the optimal configuration of silicon carbide-ultrahigh molecular weight polyethylene (SiC-UHMWPE) plates to effectively withstand 0.5 caliber Browning Machine Gun (BMG) projectiles. Six composite plates with varying thicknesses were 3D modeled and assessed for ballistic resistance using finite element analysis in Ansys Explicit Dynamics simulation software. These plates were subjected to high-velocity impacts at 930 m/s using 7.62 mm projectiles. The findings revealed that an 11 mm SiC/80 mm UHMWPE plate provided comparable bullet-stopping performance to a standard 8 mm steel 4340/60 mm UHMWPE plate, but with a significantly lower areal density. The primary mode of failure observed in penetrated samples was petaling, consistent with known behaviors of composite armor under high-impact conditions.

3D Modeling Simulation and Innovative Design of a Saw Cutting Mechanism for a Movable Buckling Machine

In this research, a sawing mechanism of a mobile buckling machine was innovatively designed for the forest resources and environmental characteristics of the northeast region of China. The northeast region of China is rich in forest resources, but the climate is cold, which puts high demands on the performance and adaptability of mechanical equipment. In this study, the three-dimensional modeling of the saw-cutting mechanism was completed by Pro/Engineer 5.0 modeling software, and an in-depth dynamics simulation analysis was carried out using dynamics simulation software. The study aims to assess the applicability of this saw-cutting mechanism in the northeast region of China, analyze its design characteristics, and explore possible directions for performance optimization. Through this study, we expect to provide valuable references for future technological innovations, as well as to promote the practical application and development of mobile buckling machines in cold regions. This research not only has regional characteristics, but also reflects the innovative idea of combining mechanical equipment design with environmental adaptability.

Design and Optimization of the Shape of a Single-person Submersible based on ANSYS

Due to the complex growth environment of wild sea cucumbers, the difficulty and low efficiency of traditional ROV identification, at present, wild sea cucumber fishing is mainly obtained through manual fishing, in order to ensure the life safety of divers and improve the fishing efficiency of sea cucumbers, new ideas and solutions for single-man submersibles suitable for shallow water operations are proposed. Under the condition of ensuring the driver's operating space, the shape and structure of an easy-to-process manned submersible are designed to optimize its resistance performance. Creo was used to establish a model of a single-man submersible for shape design, and three design schemes were proposed: scheme 1 flat spindle type, scheme 2 imitation unmanned boat type, and scheme 3 imitation airfoil type. The drag performance of the single-man submersible is simulated and analyzed by using the Fluent module in the analytical fluid dynamics simulation software Ansys, and the results show that the drag performance of scheme 3 imitation airfoil type is better than that of other schemes.The conclusion was verified by simple experiments.It provides effective reference information for the subsequent structural optimization of single-man submersibles.

The Use of Fire Dynamics System (NIST) in Determining The Architecture of Educational Spaces for Children and Young People

Objective: This study aims to investigate the potential of the Fire Dynamics Simulator (FDS) software, developed by the National Institute of Standards and Technology (NIST), as a tool to assess and improve Fire Safety (FS) in educational environments, specifically in the classrooms of CEFET in Araxá (MG), Brazil. Theoretical Framework: The research is based on the importance of fire safety in educational environments, highlighting the vulnerability of children and young people. Concepts of fire behavior, smoke propagation, and thermal conditions in buildings are addressed. Method: The methodology adopted for this research involves detailed computer simulations using FDS to analyze different fire scenarios. The simulation results were validated with the PyroSim software. Data collection was conducted through these simulations, generating robust empirical data that support the review and development of specific regulations. Results and Discussion: The results indicate that FDS is an important ally in promoting fire safety in educational buildings. The simulations showed the effectiveness of FDS in predicting fire behavior, smoke propagation, and thermal conditions, helping to prevent and minimize potential damages. The discussion contextualizes these results, highlighting the need for accurate empirical data to strengthen Brazilian fire safety legislation. Research Implications: The practical and theoretical implications of this research are discussed, providing insights into how the results can be applied to positively influence legislation, optimize architectural designs, and promote safety guidelines in educational institutions in Brazil. Originality/Value: This study significantly contributes to the advancement of knowledge and practices in FS. The originality of the research lies in the application of FDS for simulations in educational environments, offering a robust tool for evaluating and improving fire safety.

Optimization of sensor mounting position and pose in rotary kiln belt center measurement

Abstract To solve the problem that the measurement accuracy of the center of the wheel belt decreases during the adjustment of the center axis of the rotary kiln, a method of sensor installation position optimization based on dynamic simulation analysis and a simple small model is proposed and implemented in this paper. In this method, the coordinates of the laser points on the surface of the belt are obtained by using the sensor laser beam, and then the center position of the belt is obtained by fitting the coordinates of 6 laser points on the surface of the belt. Then V-rep dynamic simulation software is used to analyze the coordinates of the center position of the wheel under different sensor installation positions to find the sensor installation positions closest to the actual center of the wheel. Finally, the simulation results are verified by a simple small model. The experimental results show that this method can reduce the influence of belt deformation on the measurement of the center of the belt and find the most suitable sensor installation position. Taking the wheel with an ellipticity of 0.16% as an example, under the optimized sensor orientation, the error of the Y direction of the center of the wheel is 0.4 mm, and the error of the Z direction of the center of the wheel is 0.73 mm. By this method, the center accuracy of the existing measuring wheel is optimized from about 2 mm to less than 1 mm.

The effect of constant electric field on the crack growth process of aluminum nanosheet using molecular dynamics simulation

Aluminum nanosheets are a form of Al nanoparticle that have been recently manufactured on an industrial scale and have a variety of uses. Al nanoparticles are extensively used in a variety of sectors, including aerospace, construction, medical, chemistry, and marine industries. Crack propagation in various constructions must be investigated thoroughly for structural design purposes. Cracks in nanoparticles may occur during the production of nanosheets (NSs) or when different mechanical or thermal pressures were applied. In this work, the effect of a continuous electric field on the fracture formation process of aluminum nanosheets was investigated. For this study, molecular dynamics simulation and LAMMPS software were used. The effects of various electric fields on several parameters, including as stress, velocity (Velo), and fracture length, were explored, and numerical data were retrieved using software. The results show that the amplitude of the electric field parameter affected the atomic development of modeled Al nanosheets throughout the fracture operation. This effect resulted in atomic resonance (amplitude) fluctuations, which affected the mean interatomic forces and led the temporal evolution of atoms to converge to certain specified initial conditions. The crack length in our modeled samples ranged from 22.88 to 32.63 Å, depending on the electric field parameter (0.1–1 V/Å). Finally, it was determined that the crack growth of modeled Al nanosheets may be controlled using CEF parameters in real-world situations.

Research on the penetration performance of shaped charge jet into block stone concrete targets

Experiment and numerical simulation were conducted to investigate the penetration performance of shaped charge jet into block stone concrete targets. The experiment has shown that the jet undergoes deflection and other phenomena during its penetration of block stone concrete. Improvements have been made to the methods used by previous scholars for constructing aggregate particles, resulting in a particle model that more closely resembles the true shape of the aggregate. A novel method for judging the intersection of aggregate particles based on the Plucker coordinate system was proposed. In comparison with traditional methods, this method is not constrained by the shape of aggregate particles. By utilizing dynamic simulation software to replicate aggregate settlement during the production process of concrete targets, a 3D meso-scale model of concrete was successfully established. Numerical simulations were conducted according to the experimental settings, with the results demonstrating good consistency between the experimental and numerical simulations, thus confirming the reliability of the model and methodology presented in this article. Additionally, the numerical simulation results suggest that the aggregate content significantly influences the degree of interference, penetration depth, and damage zone range of the jet, while the impact position primarily affects the deflection of the jet. This article provides a numerical simulation method for future research on the penetration and damage mechanism of shaped charge jet considering the 3D meso-scale model of concrete.

Enhancing outdoor comfort through tensile membrane structures and pavement Surfaces: A case study report in Évora, Portugal

The Universal Thermal Climate Index (UTCI), developed in 2009 through collaboration among experts in human thermophysiology, aims to evaluate the relationship between the outdoor environment and human well-being. The case study focused on assessing the impact of shadowing and thermal masses on occupant outdoor thermal comfort as measured by the UTCI. The study specifically examined the effects of various designs of tensile membrane structures (TMS) on a U-shaped patio enclosed by nine maritime containers arranged in three groups of three levels in Évora, Portugal. The model tested fourteen TMS with varying slopes, overlap angles, lengths, repetitions, and four different pavements with distinct thermal mass layouts. The methodology employed dynamic simulation software, the energy engine EnergyPlus 2022, to assess the monthly variation of UTCI temperatures, comparing them to the scenario of an uncovered patio for each pavement configuration. The best-performing patio follows a TMS with a slope of 38.2°, an overlap of 74.4°, a length of 3.88 m, and five repetitions, accompanied by a full-concrete pavement. During winter (>9°C), the best-performing TMS underperforms against the uncovered patio by adding 1.1 °C but during summer (>26 °C), outperforms by reducing user discomfort by 9.4 °C. The global temperature deviation with the best-performing TMS sets at 3.3 °C, where the uncovered patio at 11.8 °C, is out of the comfort gap (9 °C to 26 °C) by 8.3 °C, benefiting user comfort across the year. The study highlights the potential of optimizing outdoor spaces based on UTCI measurements to create comfortable and user-friendly environments.

SIMULASI DAN ANALISIS DAMPAK PLTS SKALA BESAR DAN BESS TERHADAP SUSUT DAYA SISTEM KELISTRIKAN NUSA PENIDA

Nusa Penida island is one of the famous tourist destinations in the province of Bali. Increased tourism activities on Nusa Penida island has led to an increase in demand for electricity. In response, PT. PLN (Persero) has made great efforts to improve the quality of the power supply system in Nusa Penida to meet the increasing energy demand. As a concrete step, PT. PLN (Persero) has established a 4,2 MWp Solar Power Plant (PLTS) and a 1,84 MWh Battery Energy Storage System (BESS) to provide electrical energy to Nusa Penida. This research aims to analyze the impact of PLTS and BESS on power losses in the electrical power supply system in Nusa Penida. The electrical system of Nusa Penida simulated using the demo version of the power system dynamics simulation software. The simulation electrical system of Nusa Penida conducted under four different conditions. The results of the simulation show that both PLTS and BESS have a positive impact on power loss of electrical system in Nusa Penida.

SIMULASI DAN ANALISIS DAMPAK PLTS DAN BESS TERHADAP DROP TEGANGAN PADA SISTEM KELISTRIKAN NUSA PENIDA

Nusa Penida, Nusa Ceningan, and Nusa Lembongan or known as Tiga Nusa are very famous tourist destinations in Bali Province. The growth of tourism in Tiga Nusa has resulted in demand for electrical energy increasing every year. In order to meet the electrical energy needs in Tiga Nusa, the PLN continues to strive to improve the quality of the Nusa Penida electricity system. One of PLN's efforts is to build a Solar Power Plant that is interconnected with BESS. This research aims to analyze the effect of Solar Power Plant and BESS on voltage drops in the Nusa Penida electricity system. This research was carried out by simulation using electricity system dynamic simulation software. The simulation will be carried out with 3 scenarios. The results of this research are that Solar Power Plant interconnected with BESS has a good influence on the Nusa Penida Electricity System, as evidenced by the simulation results for scenarios 2 and 3 which have better voltage drop values compared to scenario 1.

Dynamic Response Analysis of Moving Trains Passing Through the Stationary Thunderstorm Downburst Wind

The safety of the high-speed train traveling through the stationary thunderstorm downburst wind was studied. First, a thunderstorm wind test device was used to simulate the stationary thunderstorm downburst wind. Based on the rigid model pressure measurement tests, the aerodynamic forces of the train traveling along different paths through the stationary thunderstorm downburst wind were measured. The influence of the radial distance of the crossing path on the aerodynamic force coefficients of the train was investigated. On this basis, an unsteady aerodynamic model of the high-speed train crossing through the stationary thunderstorm downburst wind was established, and dynamic response analysis was carried out using the SIMPACK multibody dynamics simulation software to explore further the safety of the high-speed train crossing through the stationary thunderstorm downburst wind. The research showed that the stationary thunderstorm downburst wind field has significant spatial variation characteristics compared with the atmospheric boundary layer wind field. When the train passes through the thunderstorm downburst wind, the radial wind speed and wind yaw angle experienced by the train constantly change, and the change curve shows a symmetrical distribution. The aerodynamic force of the train will undergo sudden loading and unloading processes, and the lateral force coefficient of the train on different paths shows a “pulse-type” variation. Moreover, the lateral force coefficient increases with the increase of wind yaw angle. Under the influence of the thunderstorm downburst wind, the variation trend of the aerodynamic force coefficients of the train is consistent with that under crosswind. However, there are significant differences in the numerical values. Therefore, it is impossible to simply use the formula for calculating the aerodynamic force coefficients of the train under crosswinds to predict the aerodynamic force coefficients of the train under the thunderstorm downburst wind. While passing through the thunderstorm downburst wind, the overturning coefficient index plays a decisive role in the safety of train operations. Train rollover is the main form of train safety accidents, while derailment accidents are not easy. The numerical results obtained in this study are significant for evaluating the operational safety while moving trains traversing the stationary thunderstorm downburst wind.

Numerical simulation and safety assessment of fires in historic timber structures based on fire load investigation

Historic timber structures face substantial fire loads and complex fire risks. Subsequent renovations and utilization may influence their fire safety performance. Therefore, accurately predicting indoor fire development in historic buildings and assessing their fire safety performance is crucial. Numerical fire simulation is currently at the forefront of analyzing and assessing fire risks in historic buildings. However, there is a shortage of globally accessible historic building fire data. This paper proposes a method to determine fire scenarios, peak heat release rates, and development curves of indoor fires in wooden historic buildings through a fire load investigation. Using the Guangzhou ancestral hall as an example, PyroSim fire dynamics simulation software is employed to calculate fire development and assess the available safe evacuation time. The simulation results are subsequently input into the Pathfinder evacuation simulation software to ascertain the required safe evacuation time for indoor occupants. A comparative assessment is conducted to evaluate the fire safety performance before and after the renovation of historic buildings. The research findings indicate that installing closed glass curtain walls in the courtyards of ancestral hall buildings in Guangzhou accelerates the infiltration of smoke during fires, leading to rapid fire spread and long-distance ignition, significantly reducing the time available for safe evacuation. Therefore, when renovating and utilizing the ancestral hall buildings in Guangzhou, the installation of ventilation and smoke extraction systems should be prioritized to slow down fire development. Additionally, controlling the number of indoor occupants is an effective management measure to mitigate fire damage in historic buildings.

LUNAR: Automated Input Generation and Analysis for Reactive LAMMPS Simulations.

Generating simulation-ready molecular models for the LAMMPS molecular dynamics (MD) simulation software package is a difficult task and impedes the more widespread and efficient use of MD in materials design and development. Fixed-bond force fields generally require manual assignment of atom types, bonded interactions, charges, and simulation domain sizes. A new LAMMPS pre- and postprocessing toolkit (LUNAR) is presented that efficiently builds molecular systems for LAMMPS. LUNAR automatically assigns atom types, generates bonded interactions, assigns charges, and provides initial configuration methods to generate large molecular systems. LUNAR can also incorporate chemical reactivity into simulations by facilitating the use of the REACTER protocol. Additionally, LUNAR provides postprocessing for free volume calculations, cure characterization calculations, and property predictions from LAMMPS thermodynamic outputs. LUNAR has been validated via building and simulation of pure epoxy and cyanate ester polymer systems with a comparison of the corresponding predicted structures and properties to benchmark values, including experimental results from the literature. LUNAR provides the tools for the computationally driven development of next-generation composite materials in the Integrated Computational Materials Engineering (ICME) and Materials Genome Initiative (MGI) frameworks. LUNAR is written in Python with the usage of NumPy and can be used via a graphical user interface, a command line interface, or an integrated design environment. LUNAR is freely available via GitHub.

Investigating the effect of heat flux on tetracycline absorption by bio-MOF-11 nanostructure: A molecular dynamics approach

Tetracycline is a type of antibiotic that falls under the category of antibiotics. Studying the absorption process of Tetracycline by bio-MOF-11 carrier is important for enhancing drug delivery efficiency, optimizing dosage, and increasing bioavailability, ultimately improving treatment outcomes and potentially leading to the development of new therapies. The present study examined the effect of variable amplitude heat flux (HF) on the bio-MOF-11 carriers' ability to absorb tetracycline. Various parameters were assessed and documented using molecular dynamics simulation and LAMMPS software, including the mean square displacement, number of drug particles, diffusion coefficient, and interaction energy. The results show that by increasing heat flux to 0.04 W/m2, the interaction energy became more negative, decreasing from −1376.35 to −1549.35 kcal/mol. Both mean square displacement and diffusion coefficient increased from 72.906 Å2 and 75.69 28 nm2/ns to 79.745 Å2 and 83.28 nm2/ns, respectively. Also, the number of penetrated Tetracycline-Drug in bio-MOF-11 carriers increased to 606, but it decreased to 520 with a further increase in HF to 0.08 W/m2. The different ways that heat affected adsorption process within the MOF structure may be the cause of this change. The first improvement in penetration can be a sign of improved drug binding and mobility at a moderate HFA. In contrast, the subsequent decrease at higher HFA levels could suggest that excessive heat disrupts the adsorption mechanism, potentially affecting the stability and efficiency of drug delivery within the system.

Study of dust pollution control effect based on orthogonal test and CFD numerical simulations.

To control the diffusion of high concentrations of coal dust during tunnel boring and minimize the threat to the life and health of coal miners, theoretical analysis, numerical simulations, and field measurements were combined in this study. First, computational fluid dynamic simulation software was used to simulate the generation of dust particles and their transport pattern in the tunnel. Subsequently, an innovative orthogonal test was performed to study the effect of four ventilation parameters [the pressure airflow rate (Q), distance between the air duct center and heading face (LA), distance between the air duct center and tunnel floor (LB), and distance between the air duct center and nearest coal wall (LC)] on dust diffusion. According to the orthogonal test results, the optimal ventilation parameters for effective dust control are as follows: Q = 1400 m3/min, LA = 7 m, LB = 2.8 m, and LC = 1 m. The optimized set of ventilation parameters was applied to the Wangpo 3206 working face. The results show that dust diffusion in the tunnel was effectively controlled and that the air quality was sufficiently improved.