scholarly journals Describing Road Booming Noise with a Hybrid Simulation Model Using a Time Segmentation of the Excitation Load Approach

Vehicles ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 469-479
Author(s):  
Michael Herrmann ◽  
Jan Kralicek ◽  
Wolfgang Stein ◽  
Frank Gauterin
Keyword(s):  
Simulation Model ◽  
Test Data ◽  
Sound Pressure ◽  
Transfer Functions ◽  
Simulation Models ◽  
Multibody Simulation ◽  
Simulation Data ◽  
The Road ◽  
Advantages And Disadvantages ◽  
Stage Of Development

One of the most important goals in vehicle acoustics is to describe the NVH behavior of a vehicle at sound pressure level using simulation models at an early stage of development. Different simulation models and methods are used for this purpose. To balance the advantages and disadvantages of the different methods, it is important to combine the simulation models. For the virtual description of the road booming noise behavior of a vehicle passing a rough road, we use a multibody simulation model excited with the elevation profile of the road in the time domain. To calculate the sound pressure inside the vehicle, the internal chassis forces of the multibody simulation model are combined with a finite element body model including the air cavity inside the cabin. The methodology for combining the chassis forces and body transfer functions to calculate the sound pressure is first validated using test data and then applied to the simulation data. The correlation of the calculated sound pressure based on test data () and based on simulation data () compared to a microphone measurement is very high.

scholarly journals 3D Modeling Method of Whole Structure for Turbo-generator Based on PROE-ANSOFT Information Interaction

2018 ◽  
Vol 10 (1) ◽  
pp. 47
Author(s):  
Yu-Ling He ◽  
Qing-Fa Meng ◽  
Ping Wang ◽  
Wen-Qiang Tao
Keyword(s):  
Simulation Model ◽  
Simulation Analysis ◽  
Simulation Models ◽  
Advantages And Disadvantages ◽  
Finite Element Software ◽  
Physical Connection ◽  
Turbo Generator ◽  
Information Interaction ◽  
3D Simulation Model ◽  
Low Efficiency

In this paper, a new method based on PROE-ANSOFT Information Interaction for building 3D model of turbo-generator structure is proposed, which can solve those problems such as low efficiency of surface modeling, the lack of physical connection relation for the automatic turbo-generator integral structure, the occurrence of insufficient memory and even crashes for imported PROE model. Taking the stator winding coil of a turbo-generator as an example, the establishment process of 3D solid model is given. On this basis, the overall structure of turbo-generator in the ANSOFT working platform is completed. And the advantages and disadvantages of five kinds of simulation models in ANSOFT working platform are compared and analyzed. The results show that the 3D simulation model drawn by this method can be no longer limited to the special solution environment of electromagnetic field symmetry. Meanwhile, this model can simulate the real physical connection relationship, and complete the division of the simulation model, which will be helpful for the further simulation analysis of the finite element software.

Simulation Models in Forest Management and Harvesting

1968 ◽  
Vol 44 (1) ◽  
pp. 7-13 ◽  
Author(s):  
R. M. Newnham
Keyword(s):  
Forest Management ◽  
Simulation Model ◽  
Stand Structure ◽  
Simulation Models ◽  
Stand Development ◽  
Operating Characteristics ◽  
Individual Tree ◽  
Harvesting Time ◽  
Advantages And Disadvantages

The advantages and disadvantages of simulation models are described and examples are given of their use in forestry. Stand models and a simulation model for pulpwood harvesting machines are described in some detail. Stand models simulate the growth of a stand on an individual tree basis and can be used for testing the effect of different silvicultural operations on subsequent stand development. The harvesting simulation models imitate the passage of a harvesting machine through a stand of pulpwood. They can be used to test the effect on harvesting time of using machines of different sizes and operating characteristics. The effect of stand structure on harvesting time can also be tested.

scholarly journals Development of a Spoon Motion Navigation Algorithm for the Mealtime Assistant Simulator

2021 ◽  
Vol 33 (4) ◽  
pp. 768-776
Author(s):  
Atsushi Mitani ◽  
Masumi Muramatsu ◽  
◽  
Keyword(s):  
Simulation Model ◽  
Evaluation System ◽  
Transfer Functions ◽  
Oral Care ◽  
Simulation Models ◽  
Educational Process ◽  
Care Process ◽  
Elderly Persons ◽  
Clinical Environment ◽  
Pressing Force

In aging society like Japan, maintaining the quality of life (QOL) is an important objective. The oral cavity has various significant functions that contribute to the QOL. Elderly people are susceptible to the swallowing disorders owing to various factors associated with advancing age. In such cases, mealtime assistance can provide elderly persons appropriate eating situations. Thus, mealtime assistance skills are essential for students in nursing and caregiver education. Recently, simulation education has attracted attention as an effective educational process for nursing and caregiver students before their clinical practice in a hospital or care house. In this educational process, a patient model that mimics specific symptoms called the simulation model, is used to learn the symptoms and its care process in the same clinical environment as actual. We have attempted to develop several oral care simulation models, and we have earlier developed a prototype of mealtime assistance simulation model. This simulation model had a tongue model with a sensor system to detect spoon motions, and its fundamental functions were evaluated via spoon detection experiments. Based on the earlier achievements, in this study, we develop an evaluation system of feeding skill using a spoon. The pressing force and position by spoon on the tongue model were estimated by transfer functions derived from experiments. In addition, we developed an algorithm that leads students’ spoon position and pressing force in the correct position.

scholarly journals Improvement of Efficiency of Operation of Forest-Motor Vehicles Based by the Device for Controlling the Swing Axle of the Trailer

2017 ◽  
Vol 7 (3) ◽  
pp. 210-218
Author(s):  
Петр Попиков ◽  
P. Popikov ◽  
Виктор Белозоров ◽  
V. Belozorov ◽  
Константин Меняйлов ◽  
...  
Keyword(s):  
Transfer Functions ◽  
Road Accident ◽  
Economic Conditions ◽  
Motor Vehicles ◽  
Reference Surface ◽  
The Road ◽  
Advantages And Disadvantages ◽  
Factors Influencing ◽  
Systemic Design ◽  
Economic Comparison

The concept of systemic design of forest machines in the new economic conditions is proposed in the article. The main provisions of the choice of a mechanism for controlling the trailer of a road train on the basis of a technical and economic comparison of options are given. The main characteristics of the management of the road train and the efficiency of the technological process of transportation are determined. The proposed work deals with the issues of controllability of vehicles, which is of considerable interest for the purpose of using such equipment for forest machines, which would provide movement over a different reference surface (snow, sand, marsh etc). It is proposed to improve the electropneumatic design of the trailer drive, taking into account the numerous and changing factors. The analysis of timber car trailer constructions is given. The advantages and disadvantages of wood transportation by multi-tier road train are considered. The main types of road sections. The article analyzes the factors influencing the operational condition of roads. The road junctions are the places where the road accident most often occurs. The probability of ensuring reliability of functioning of separate elements of the highway and also road in general in time of close conditions of operation with technical or economic advantages in comparison with traditional decisions is considered. A graph is presented for determining the speed of the road train according to the proposed method for various conditions and factors. The method of finding the transfer functions of a complex multi-mass mechanical system "VAD" is proposed. The economic efficiency of the truck fleet is determined by the specific costs of transportation of timber, representing the ratio of the sums of costs.

scholarly journals Guidelines to Calibrate a Multi-Residential Building Simulation Model Addressing Overheating Evaluation and Residents’ Influence

Buildings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 242
Author(s):  
Christoph Schünemann ◽  
David Schiela ◽  
Regine Ortlepp
Keyword(s):  
Simulation Model ◽  
Time Window ◽  
Residential Building ◽  
Simulation Models ◽  
Building Simulation ◽  
Night Time ◽  
Building Performance Simulation ◽  
Starting Point ◽  
3D Simulation Model ◽  
Building Physics

Can building performance simulation reproduce measured summertime indoor conditions of a multi-residential building in good conformity? This question is answered by calibrating simulated to monitored room temperatures of several rooms of a multi-residential building for an entire summer in two process steps. First, we did a calibration for several days without the residents being present to validate the building physics of the 3D simulation model. Second, the simulations were calibrated for the entire summer period, including the residents’ impact on evolving room temperature and overheating. As a result, a high degree of conformity between simulation and measurement could be achieved for all monitored rooms. The credibility of our results was secured by a detailed sensitivity analysis under varying meteorological conditions, shading situations, and window ventilation or room use in the simulation model. For top floor dwellings, a high overheating intensity was evoked by a combination of insufficient use of night-time window ventilation and non-heat-adapted residential behavior in combination with high solar gains and low heat storage capacities. Finally, the overall findings were merged into a process guideline to describe how a step-by-step calibration of residential building simulation models can be done. This guideline is intended to be a starting point for future discussions about the validity of the simplified boundary conditions which are often used in present-day standard overheating assessment.

Mechanical Performance Simulation Model Based on PDM

2013 ◽  
Vol 300-301 ◽  
pp. 32-35
Author(s):  
Xiao Wen Zeng ◽  
Cheng Zeng ◽  
Bing Han
Keyword(s):  
Simulation Model ◽  
Mechanical Performance ◽  
Product Structure ◽  
Dynamics Simulation ◽  
Simulation Data ◽  
Performance Simulation ◽  
Collaborative Simulation ◽  
Complex Simulation ◽  
Mechanical Dynamics ◽  
Relationship Of

In order to manage the complex simulation data management in the process of mechanical dynamics simulation, a new management model was presented which is Performance Simulation Model(PSM). The model was based on PDM product structure and the concepts and elements of PSM were defined in this paper. Furthermore, the functional framework of PSM was proposed which based on the hierarchical relationship of product structure and the data stream relationship of data structure matrix. Finally, PSM was applied on ship planetary reducer collaborative simulation platform. The result indicates that the simulation data in mechanical collaborative simulation are managed by PSM, and the problem of interaction between collaborative simulation and PDM is solved.

Settings, Experimentation and Evaluation of the Simulation Models

2013 ◽  
Vol 309 ◽  
pp. 366-371 ◽  
Author(s):  
František Manlig ◽  
Radek Havlik ◽  
Alena Gottwaldova
Keyword(s):  
Simulation Model ◽  
New Technology ◽  
Simulation Models ◽  
Manufacturing Processes ◽  
Customer Requirements ◽  
Evaluation Functions ◽  
Operational Management ◽  
Minimum Number ◽  
User Friendly ◽  
Setting Parameters

This paper deals with research in computer simulation of manufacturing processes. The paper summarizes the procedures associated with developing the model, experimenting with and evaluating the model results. The key area is of experimentation with the simulation model and evaluation using indicators or multi-criteria functions. With regards to the experiment the crucial variables are the simulation model. The key ideas are to set the number of variables, depending on what a given simulation will be. For example, when introducing new technology into production, modify the type of warehouse, saving workers, thus economizing. The simulation models for the operational management uses simplified models, if possible, a minimum number of variables to obtain the result in shortest possible time. These models are more user friendly and the course will be conducted mostly in the background. An example of a criteria function is the number of parts produced or production time. Multi-criteria function has given us the opportunity to make better quality decisions. It is based on the composition of several parameters, including their weight to one end point. The type of evaluation functions, whether it is an indicator or criteria function is selected and based on customer requirements. In most cases it is recommended to use the multi-dimensional function. It gives us a more comprehensive view of the results from the model and facilitates decision-making. The result of this paper is a display of setting parameters for the experimentation on a sample model. Furthermore, the comparisons of results with a multi-criteria objective function and one-criterion indicator.

A Method to Define the Best Weld Sequence Using a Limited Number of Welding Simulation Analysis

2015 ◽  
Author(s):  
Mahyar Asadi ◽  
Ghazi Alsoruji
Keyword(s):  
Simulation Model ◽  
Surrogate Model ◽  
Simulation Analysis ◽  
Combinatorial Problem ◽  
Fem Analysis ◽  
Simulation Models ◽  
Computational Time ◽  
Optimal Sequence ◽  
Welded Structure ◽  
Welding Sequence

Weld sequence optimization, which is determining the best (and worst) welding sequence for welding work pieces, is a very common problem in welding design. The solution for such a combinatorial problem is limited by available resources. Although there are fast simulation models that support sequencing design, still it takes long because of many possible combinations, e.g. millions in a welded structure involving 10 passes. It is not feasible to choose the optimal sequence by evaluating all possible combinations, therefore this paper employs surrogate modeling that partially explores the design space and constructs an approximation model from some combinations of solutions of the expensive simulation model to mimic the behavior of the simulation model as closely as possible but at a much lower computational time and cost. This surrogate model, then, could be used to approximate the behavior of the other combinations and to find the best (and worst) sequence in terms of distortion. The technique is developed and tested on a simple panel structure with 4 weld passes, but essentially can be generalized to many weld passes. A comparison between the results of the surrogate model and the full transient FEM analysis all possible combinations shows the accuracy of the algorithm/model.

Modeling and Estimation of Headway Distributions

1997 ◽  
Vol 1591 (1) ◽  
pp. 14-22 ◽  
Author(s):  
Serge P. Hoogendoorn ◽  
Hein Botma
Keyword(s):  
Estimation Method ◽  
Simulation Models ◽  
Independent Random Variables ◽  
Microscopic Simulation ◽  
Simple Analysis ◽  
Rural Roads ◽  
The Road ◽  
Road Capacity ◽  
Measurement Location ◽  
Fourier Series Analysis

A simple analysis to derive Branston’s generalized queueing model for (time-) headway distributions is presented. It is assumed that the total headway is the sum of two independent random variables: the empty zone and the free-flowing headway. The parameters of the model can be used to examine various characteristics of both the road (e.g., capacity) and driver-vehicle combinations (e.g., following behavior). Furthermore, the model can be applied to vehicle generation in microscopic simulation models and to safety analysis. To estimate the different parameters in the model, a new estimation method is proposed. This method, which was developed on the basis of Fourier-series analysis, was successfully applied to measurements collected on two-lane rural roads. The method was found to be both computationally less demanding and more robust than traditional parameter techniques procedures, such as maximum likelihood. In addition, the method provides more accurate results. Parameters in the model were examined with the developed estimation method. Estimates of these parameters at a specific period and a specific measurement location were to some extent transferable to other periods and locations. Application of the method to road capacity estimation is discussed.

Rotorcraft Lateral-Directional Oscillations: The Anatomy of a Nuisance Mode

2021 ◽  
Author(s):  
Dheeraj Agarwal ◽  
Linghai Lu ◽  
Gareth D. Padfield ◽  
Mark D. White ◽  
Neil Cameron
Keyword(s):  
Simulation Model ◽  
Simulation Models ◽  
Flight Test ◽  
Flight Simulation ◽  
Stability And Control ◽  
Systems Research ◽  
Control Derivatives ◽  
Research Aircraft ◽  
Level Of Understanding ◽  
And Control

High-fidelity rotorcraft flight simulation relies on the availability of a quality flight model that further demands a good level of understanding of the complexities arising from aerodynamic couplings and interference effects. One such example is the difficulty in the prediction of the characteristics of the rotorcraft lateral-directional oscillation (LDO) mode in simulation. Achieving an acceptable level of the damping of this mode is a design challenge requiring simulation models with sufficient fidelity that reveal sources of destabilizing effects. This paper is focused on using System Identification to highlight such fidelity issues using Liverpool's FLIGHTLAB Bell 412 simulation model and in-flight LDO measurements from the bare airframe National Research Council's (Canada) Advanced Systems Research Aircraft. The simulation model was renovated to improve the fidelity of the model. The results show a close match between the identified models and flight test for the LDO mode frequency and damping. Comparison of identified stability and control derivatives with those predicted by the simulation model highlight areas of good and poor fidelity.

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