Dynamic Load Simulation Research Articles

A general framework for modeling shared autonomous vehicles with dynamic network-loading and dynamic ride-sharing application

Shared autonomous vehicles (SAVs) could provide low-cost service to travelers and possibly replace the need for personal vehicles. Previous studies found that each SAV could service multiple travelers, but many used unrealistic congestion models, networks, and/or travel demands. The purpose of this paper is to provide a method for future research to use realistic flow models to obtain more accurate predictions about SAV benefits. This paper presents an event-based framework for implementing SAV behavior in existing traffic simulation models. We demonstrate this framework in a cell transmission model-based dynamic network loading simulator. We also study a heuristic approach for dynamic ride-sharing. We compared personal vehicles and SAV scenarios on the downtown Austin city network. Without dynamic ride-sharing, the additional empty repositioning trips made by SAVs increased congestion and travel times. However, dynamic ride-sharing resulted in travel times comparable to those of personal vehicles because ride-sharing reduced vehicular demand. Overall, the results show that using realistic traffic flow models greatly affects the predictions of how SAVs will affect traffic congestion and travel patterns. Future work should use a framework such as the one in this paper to integrate SAVs with established traffic flow simulators.

IMPROVEMENT OF THE SUPPORTING STRUCTURE OF PLATFORM CAR FOR HIGHER EFFICIENCY OF CONTAINER TRANSPORTATIONS

Purpose. The article is aimed to improve supporting structures of the platform car to increase the efficiency of container transportations. Methodology. In order to achieve the objective, the strength investigations of the universal platform car of the model 13-401 were conducted, strength reserves of the supporting elements were defined, and more optimal profiles of basic longitudinal beams of the frame in terms of the minimum material capacity were proposed. Decision correctness was confirmed by the strength calculation of the platform car supporting structure at basic loading operational modes and fatigue taking into account the research database of 107 cycles. It has been proposed to equip a platform car with swing fitting stops for fastening containers on the frame, which allows transportation of 20ft and 40ft containers. In order to improve container transportation efficiency along international transport corridors running through Ukraine, a platform car of articulated type has been designed on the base of the improved platform car structure. The mathematical simulation of dynamic loads of the platform car with containers (two 1CC containers) at operational loading modes has been carried out, the maximum accelerations influencing the support structure have been defined, and their multiple values have been considered in computer simulation of the strength of the platform car of articulated type. Findings. The support structure of the platform car of articulated type on the basis of the standard platform car has been developed. Refined values of dynamic loads influencing supporting structure the platform car of articulated type with containers at operational loading modes have been obtained; the maximum equivalent stresses in the platform car support structure have been defined. Originality and practical value. A mathematical model of displacements for a platform car of articulated type with containers at operational loading modes of supporting structure has been proposed. The strength model of the supporting structure for the platform car of articulated type based on the standard platform car has been developed. Results of the research can be used in designing of platform cars of articulated type to provide their strength at mixed transportations.

Study on Building Energy Load Prediction Based on Monitoring Data

Energy planning is important for development areas in need of new energy distribution systems. However, the current energy planning still lacks effective data support and necessary assessment, and the energy load is usually overestimated by using the static load index meth-od or dynamic building energy load simulation, which leads to big equipment capacity at the design stage and high energy consumption during the operation stage. There is an urgent need to use real data to support the energy load estimation for energy planning. In this paper, a new model is described that produces heating and cooling load profiles for building categories based on monitoring data. The method is based on simultaneous metered delivered energy on hourly basis as well as background information of the metered buildings. The five-parameter model considering the relationships between energy and mean outside temperature were developed. The electricity consumption data routinely collected from over fifty campus buildings was selected for case study. The proposed model is used to estimate the energy loads for the selected campus region for case study, which are proven accurate with the difference of less than 5% of the monitoring result. This study provides a new procedure to estimate heating and cooling load for energy planning for community energy planning.

Dynamic compressive strength and crushing properties of expanded polystyrene foam for different strain rates and different temperatures

In this study, static and dynamic compression and crushing tests were conducted on expanded polystyrene (EPS) foam for material characterisation at high strain rates. This was done to obtain the stress-strain curve for different temperatures and densities. An influence of the strain rate on the experimental data was shown. The resulting curves for modelling were extracted from the experimental data, which were obtained from high speed drop tower tests. The methodology for the processing of the experimental data for use in the finite element (FE) modelling was presented. The foam material model of LS-Dyna was used to simulate the dynamic compression process. This model is dedicated to modelling crushable foam with optional damping, tension cut-off, and strain rate effects. The adjustment of the material parameters for successful modelling has been reported. This FE model of EPS foam was validated with experimental data using impact on a “kerbstone” support. This model can be applied for simulation of dynamic loads on a bicycle helmet. It is useful for designing a reliable bicycle helmet geometry for different types of accidents.

Simulation of Dynamic Load Balancing Algorithms

Simulation of Dynamic Load Balancing Algorithms

Journal of Dynamic Behavior of Materials: A New Forum for Knowledge Exchange on Dynamic Material Response, High Strain-Rate Effects, Shock, and Materials Under Extreme Loading

We are excited to introduce the Journal of Dynamic Behavior of Materials (JDBM) as the new journal of the Society for Experimental Mechanics (SEM). We wish to invite you to submit your best work on the study of the dynamic behavior of materials to the journal and help in getting the word out to your colleagues. Information on the journal can be found at http://springer.com/40870. The field of dynamic behavior of materials is undergoing a revolution with increasing interdisciplinary focus and unprecedented new level of diagnosis at the bench scale and numerous user facilities. Classic loading techniques including split Hopkinson pressure (Kolsky) bar, gas/ powder guns, and high-explosives are being pushed to increased levels of precision, linked with new and novel diagnostics enabling previously unattainable levels of in situ measurement combined with advanced high resolution and three-dimensional post-mortem observation. National User Facilities are enhancing their capacities for studying materials in extremes with new facilities being developed ranging from SLAC’s Linac Coherent Light Source, the Dynamic Compression Sector at the Advanced Photon Source at Argonne National Laboratory, the Z-Machine at Sandia National Laboratories, the National Ignition Facility at Lawrence Livermore National Laboratory, and Matter-Radiation Interactions in Extremes at Los Alamos National Laboratory. An exciting collaboration at GSI in Darmstadt is incorporating expertise from pRad and LANSCE at Los Alamos National Laboratory in the USA and the Institute for Theoretical and Experimental Physics in Russia using the PRIOR microscope with great potential for studying dynamic materials processes. The Diamond Light Source located at the Harwell Science and Innovation Campus in the UK has been offering great levels of postmortem investigation of damage from dynamic loading. Exciting capabilities exist at these and other facilities around the world to advance the state-of-the-art for studies of dynamic behavior of materials. Advances in modeling & simulation of dynamic loading and material response have paralleled these experimental advances. Continued evolution in computing hardware is enabling calculations with extraordinary fidelity in representation of highly coupled complex physics. Great advances have been made in density functional theory, molecular dynamics, and dislocation dynamics based material models. Simulations based on these theories have historically had to be performed at very high strain-rates and in very short time and length scales. Advances in these models and the hardware on which these simulations are performed have brought them into line with the regimes of many platforms for dynamic experiments. New theories and models of material behavior are being developed to take advantage of understanding material at the mesoscale. Continuum level constitutive models are being proposed and developed with greater levels of physical underpinning and predictive ability. The state-of-the art in modeling & simulation and experiments along with the interdisciplinary approach to modern science and engineering have lead to significant payoff from hybrid experimental-computational approaches. Advances in simulation are enabling the development and optimization of experiments, with better understanding of the underlying physics and data capture. Conversely, advances in experimentation are pushing better models, codes, and simulations. The JDBM offers a single source to bring this broad, vibrant international community together. This peer E. N. Brown (&) Los Alamos National Laboratory, Los Alamos, NM 87545, USA e-mail: en_brown@lanl.gov

Vibration and dynamic loads in external gear pumps

This paper presents the model for simulation of vibration and dynamic loads in external gear pumps. The calculation has been carried out in Matlab/Simulink program. The vibrations of gears are excited due to the variable pressure forces and variable stiffness of the gearing. In this model the stiffness and damping coefficient of sliding bearings as well as the bending stiffness of gear wheels have been included. The influence of pressure and rotational speed on the dynamic forces in the bearings have been analyzed.

DTALite: A queue-based mesoscopic traffic simulator for fast model evaluation and calibration

AbstractA number of emerging dynamic traffic analysis applications, such as regional or statewide traffic assignment, require a theoretically rigorous and computationally efficient model to describe the propagation and dissipation of system congestion with bottleneck capacity constraints. An open-source light-weight dynamic traffic assignment (DTA) package, namely DTALite, has been developed to allow a rapid utilization of advanced dynamic traffic analysis capabilities. This paper describes its three major modeling components: (1) a light-weight dynamic network loading simulator that embeds Newell’s simplified kinematic wave model; (2) a mesoscopic agent-based DTA procedure to incorporate driver’s heterogeneity; and (3) an integrated traffic assignment and origin–destination demand calibration system that can iteratively adjust path flow volume and distribution to match the observed traffic counts. A number of real-world test cases are described to demonstrate the effectiveness and performance of the prop...

The Software of Air-Conditioning Dynamic Load Simulation and Forecasting for the Walls of Building

All-year thermal dynamic load simulating and energy consumption analysis for new energy-saving building is very important in building environment. According to thermal instantaneous response factors method, the paper develop a software to calculate air conditioning cooling load temperature and the dynamic thermal basic data that involve thermal response factors, periodic response factors, Z transfer function coefficient for new energy ­saving walls in building, which will provide the referable scientific foundation for all-year new thermal dynamic load simulation, energy consumption analysis, building environment systems control, carrying through farther research on thermal particularity and general particularity evaluation for new energy ­saving walls building. based on which, we will not only expediently design system of building energy, but also analyze building energy consumption and carry through scientific energy management. The study will provide the referable scientific foundation for carrying through farther research on thermal particularity and general particularity evaluation for new energy saving walls building.

Simulation and Analysis of Annual Dynamic Air Conditioning Load for Multi-Zone Building

Applying TRNSYS, this paper introduced a numerical simulation of annual dynamic air conditioning load for the standard floor, the refuge floor and the top floor of a high-rise building in Tianjin. Results suggest that even though the refuge floor and the top floor share similar load characteristics of heating & cooling air-conditioning, they have different load sizes, and the load characteristic of the standard floor is different from them.

Simulation Analysis of Primary Energy Ratio for Air-Source Gas Engine-Driven Heat Pump

Based on the simulation of the air conditioning construction dynamic load and simulation calculation of air-source gas engine-driven heat pump (GEHP), the air-source GEHP air conditioning in winter, summer and the annual primary energy ratio are analyzed in simulation with the combination of a hotel building in Tianjin. Firstly, DeST software is used to simulate all-year hourly air conditioning load of the building. Then air-source GEHP simulation model [1] is used to calculate the annual hourly gas consumption and the amount of GEHP's gas consumption in winter, summer and a total year afterwards can be got. At the same time, by the analysis of waste heat recovery of gas engine-driven, primary energy ratio for air-source GEHP in Tianjin is given under the different waste heat recovery of winter, summer and the annual.

Impact Loading Analysis of Light Sport Aircraft Landing Gear

This paper examined the critical loading condition of a light sport aircrafts main landing gear during the impact loading condition. The new category airplane was established by the FAA in 2004. The light sport aircraft has great market demand for personnel entertainment purpose and regional transportation. The main object of this research was to establish a static and dynamic loading simulation model for the aluminum alloy landing gear of a light sport aircraft. This work also examined the critical loading parameters of the main landing gear, including the maximum take-off weight and maximum stall speed. The analysis was performed using ANSYS and LS-DYNA to establish the finite element model after simplifying the geometric characteristics and verifying the results by energy conservation, hourglass energy, and sliding energy. The study tested aluminum plates with a thickness from 15~25 mm. The results showed all the samples could sustain the required loading condition, except for the thickness of 15mm that failed under impact loading. The simulation model provides a cost-saving process compared to a real crashworthiness drop test to test the main landing gears compliance with regulations.

The Effects of Dynamic Loading on Hysteretic Behavior of Frictional Dampers

During an earthquake excitation, a frictional damper may experience many cycles of dynamic loading. The effects of wear and heat induced by the cyclic loading result in the possible decay of the slippage load which subsequently reduce the energy absorption of the damper. In this paper, the effect of dynamic loading on hysteretic behavior of a special kind of frictional damper, namely, cylindrical frictional damper (CFD), is investigated by experimental means as well as numerical models which also account for coupled thermal-structural interaction. The damper is deemed to be more susceptible to thermal deformations due to the shrink-fit mechanism by which the device is assembled. The numerical models are validated experimentally and may be utilized for simulation of dynamic cyclic loading on frictional dampers. The results demonstrate that the slippage load is reduced gradually when subjected to consecutive cycles. This drift is attributed to thermal deformation. The verified numerical models are used to improve the geometry of the CFD. With the geometrical improvements implemented, the subsequent numerical studies confirmed that almost no degradation of the slippage load occurred. Furthermore, a dimensionless parameter is introduced by the authors which shows the effect of wear on the response of CFDs.

Модель интенсивного динамического нагружения карбидов с различными стехиометрическими составами

Модель интенсивного динамического нагружения карбидов с различными стехиометрическими составами

Design and Analysis of Power Head Axial Servo Loading System

Power head is the main motive mechanism of rotary drilling rig. High axial pressure and high frequency is one of its typical working conditions. Axial loading test is a key point in power head performance tests. Overall design, system theoretical analysis and simulation of power head axial loading system were carried out. The bond graph model and state equations of power head axial servo loading system were built on the basis of bond graph theory. Hydraulic system simulation model was constructed and axial steady-state and dynamic loading simulation was made by use of hydraulic simulation software. The maximum axial steady-state load is up to 450kN and the dynamic frequency is 20Hz, both of which can meet the technical requirements. The simulation validates the feasibility of the scheme about power head axial loading system and it provides theory and practice guidance for perfecting the loading system. DOI: http://dx.doi.org/10.11591/telkomnika.v11i10.3390

The Achievement of Dynamic Load Simulator of Servo Mechanism of Multiple DOF Thrust Vector

In order to better analyze the load resonant characteristic of thrust vector servo mechanism of spacecrafts, multiple DOF mathematical models were established. Combined with the need of simulated actual conditions for ground tests, a comprehensive load simulator containing mechanical and hydraulic load was presented. The simulation results show that, the dynamic characteristics of output load displacement of the simulator is in agreement with the characteristics of actual system. The simulation and experimental results verify the feasibility of this load simulator structure, which could provide design reference for developing equipment of thrust vector control system for ground tests.

Design of a laboratory hydraulic device for testing of hydraulic pumps

The present contribution deals with solves problem of research of testing device to monitor of hydrostatic pumps durability about dynamic loading under laboratory conditions. When carrying out the design of testing device are based on load characteristics of tractor hydraulic circuit, the individual characteristics of hydraulic components and performed calculations. Load characteristics on the tractors CASE IH Magnum 310, JOHN DEERE 8100, ZETOR FORTERRA 114 41 and Fendt 926 Vario were measured. Design of a hydraulic laboratory device is based on the need for testing new types of hydraulic pumps or various types of hydraulic fluids. When creating of hydraulic device we focused on testing hydraulic pumps used in agricultural and forestry tractors. Proportional pressure control valve is an active member of the hydraulic device, which provides change of a continuous control signal into relative pressure of operating fluid. The advantage of a designed hydraulic system is possibility of simulation of dynamic operating loading, which is obtained by measurement under real conditions, and thereby creates laboratory conditions as close to real conditions as possible. The laboratory device is constructed at the Department of Transport and Handling, Faculty of Engineering, Slovak University of Agriculture in Nitra.

Research on the Effect of Width-Span Ratio on the Bridge Impact Coefficient

In this paper, the bridge impact coefficient was researched under conditions of the same section form and different width-span ratio. Five bridge models were set up based on the finite element method. Static and dynamic load simulation analysis for the same form of bridge was conducted firstly. Then the impact coefficient was calculated. Finally, According to the variation of impact coefficient along with the bridge width-span ratio, the method of probabilistic statistical regression analysis is applied to analyze the changing rule of the impact coefficient change with width-span ratio. Results showed that the influence of width-span ratio on impact coefficient should considered preferably for ordinary highway bridges with its width-span ratio less than 1. But for taxiway bridges which the width-span ratio is generally between 2 to 3, the influence of width-span ratio on impact coefficient can be ignored.

Research on propeller dynamic load simulation system of electric propulsion ship

A dynamic marine propeller simulation system was developed, which is utilized for meeting the experimental requirement of theory research and engineering design of marine electric propulsion system. By applying an actual ship parameter and its accurate propeller J′ ∼ KT′ and J′ ∼ KP′ curve data, functional experiments based on the simulation system were carried out. The experiment results showed that the system can correctly emulate the propeller characteristics, produce the dynamic and steady performances of the propeller under different navigation modes, and present actual load torque for electric propulsion motor.

Simulation of Dynamic Heat Load for Underground Structure Envelope

Analyses the mechanisms of dynamic heat transfer in the underground works envelope and the simplified calculation method for heat transfer. With the cooperative function of MATLAB, Simulink and COMSOL simulate the dynamic variation of the heat load and validate the simulation results by an experiment.