Dynamic Analysis of Slider Mechanisms With Consideration of Frictional Effect in the Slider

2018 ◽  
Author(s):  
Jianyou Han ◽  
Yang Cao ◽  
Penghao Li
Keyword(s):  
Dynamic Analysis ◽  
Friction Force ◽  
Center Of Mass ◽  
Frictional Effect ◽  
Hinge Point ◽  
Shear Mechanism ◽  
Dynamic Analyses ◽  
Rotation Motion ◽  
Application Scope

This paper deals with dynamic analysis of three methods for the slider in mechanisms. Three methods are introduced under three conditions (the influence of friction force is considered, the slider’s center of mass is not coincide with the hinge point, the slider and its guide have rotation motion). The dynamic analyses of the crank slider mechanism and the flying shear mechanism are given as examples by a developed software based on Visual C++ environment, and application scope of the three methods is concluded at the end of the paper. These results are useful for analyzing and designing mechanisms with sliders, such as choosing suitable slider materials or actuators.

scholarly journals Dynamic analysis and motion control of spinning tether system during its Earth to Mars flight

2021 ◽  
Vol 5 (1) ◽  
pp. 27-34
Author(s):  
H. Lu ◽  
C. Wang ◽  
Yu. M. Zabolotnov
Keyword(s):  
Dynamic Analysis ◽  
Motion Control ◽  
Center Of Mass ◽  
Angular Speed ◽  
Artificial Gravity ◽  
Jet Engines ◽  
Interplanetary Trajectory ◽  
Material Points ◽  
Spinning Tether ◽  
Interplanetary Mission

The dynamic analysis and motion control of a spinning tether system for an interplanetary mission to Mars is considered. The space system consists of two spacecraft connected by a tether with thrusts to control its movement. The movements of the tether system in the sphere of action of the Earth, on the interplanetary trajectory and in the sphere of action of Mars are consistently analyzed. In near-Earth orbit, the transfer of the system into rotation with the help of jet engines installed on the end spacecrafts is considered. The spin of the system is used to create artificial gravity during the interplanetary flight. The tether system spins in the plane perpendicular to the plane of the orbital motion of the center of mass of the system. To describe spatial motion of the system, a mathematical model is used, in which the tether is represented as a set of material points with viscoelastic unilateral mechanical connections. When calculating the movement of the system, an approach based on the method of spheres of action is used. Spacecrafts are considered as material points. The level of gravity and spin of tether system is controlled by thrusters. The structure of the controller for controlling the angular speed of rotation of the tether system is proposed. The simulation results are presented to confirm the effectiveness of the proposed control algorithm, which provides a given level of artificial gravity for th e interplanetary mission under consideration.

scholarly journals Hybrid-Based Analysis Impact on Ransomware Detection for Android Systems

2021 ◽  
Vol 11 (22) ◽  
pp. 10976
Author(s):  
Rana Almohaini ◽  
Iman Almomani ◽  
Aala AlKhayer
Keyword(s):  
Dynamic Analysis ◽  
Static Analysis ◽  
Hybrid System ◽  
State Of The Art ◽  
Detection System ◽  
Detection Accuracy ◽  
Accuracy Rate ◽  
Hybrid Detection ◽  
Dynamic Analyses ◽  
Data Files

Android ransomware is one of the most threatening attacks that is increasing at an alarming rate. Ransomware attacks usually target Android users by either locking their devices or encrypting their data files and then requesting them to pay money to unlock the devices or recover the files back. Existing solutions for detecting ransomware mainly use static analysis. However, limited approaches apply dynamic analysis specifically for ransomware detection. Furthermore, the performance of these approaches is either poor or often fails in the presence of code obfuscation techniques or benign applications that use cryptography methods for their APIs usage. Additionally, most of them are unable to detect ransomware attacks at early stages. Therefore, this paper proposes a hybrid detection system that effectively utilizes both static and dynamic analyses to detect ransomware with high accuracy. For the static analysis, the proposed hybrid system considered more than 70 state-of-the-art antivirus engines. For the dynamic analysis, this research explored the existing dynamic tools and conducted an in-depth comparative study to find the proper tool to integrate it in detecting ransomware whenever needed. To evaluate the performance of the proposed hybrid system, we analyzed statically and dynamically over one hundred ransomware samples. These samples originated from 10 different ransomware families. The experiments’ results revealed that static analysis achieved almost half of the detection accuracy—ranging around 40–55%, compared to the dynamic analysis, which reached a 100% accuracy rate. Moreover, this research reports some of the high API classes, methods, and permissions used in these ransomware apps. Finally, some case studies are highlighted, including failed running apps and crypto-ransomware patterns.

Dynamic Shock Analysis of Shipboard Equipment

1967 ◽  
Vol 4 (04) ◽  
pp. 331-354
Author(s):  
R. L. Harrington ◽  
W. S. Vorus
Keyword(s):  
Mathematical Models ◽  
Dynamic Analysis ◽  
Analysis Method ◽  
Dynamic Analyses ◽  
Shock Resistance ◽  
Computational Procedures

A description and evaluation of the dynamic analysis method of determining the shock resistance of shipboard equipment is given. Development of equipment mathematical models is treated in detail, and the computational procedures used in conducting dynamic analyses are illustrated. Considerations in the preparation of dynamic-analysis reports are discussed. Discussers R. S. Adelizzi G. W. Bishop V. T. Boatwright K. J. Calvin C. Dotson Capt. H. C. Field, Jr., USND. W. Ginter O. Gould D. M. Gray K. Gyswyt R. T. Hawley RADM L. V. Honsinger, USN(Ret.) C. Lee J. C. Lester C. Li W. A. Littlejohn N. J. Monroe A. Morrone B. Novak E. W. Palmer C. G. Puffenburger L. L. Salter H.M. Schauer J. R. Sullivan J. D. Swannack C. Y. Tiao H. H. Ward W. P. Welch J. B. Woodward, III

The Impact of Nudging in the Meteorological Model for Retrospective Air Quality Simulations. Part II: Evaluating Collocated Meteorological and Air Quality Observations

2008 ◽  
Vol 47 (7) ◽  
pp. 1868-1887 ◽  
Author(s):  
Tanya L. Otte
Keyword(s):  
Air Quality ◽  
Dynamic Analysis ◽  
Air Quality Modeling ◽  
Shortwave Radiation ◽  
Error Patterns ◽  
Ozone Prediction ◽  
Quality Modeling ◽  
Dynamic Analyses ◽  
The Impact ◽  
Over Time

Abstract For air quality modeling, it is important that the meteorological fields that are derived from meteorological models reflect the best characterization of the atmosphere. It is well known that the accuracy and overall representation of the modeled meteorological fields can be improved for retrospective simulations by creating dynamic analyses in which Newtonian relaxation, or “nudging,” is used throughout the simulation period. This article, the second of two parts, provides additional insight into the value of using nudging-based data assimilation for dynamic analysis in the meteorological fields for air quality modeling. Meteorological simulations are generated by the fifth-generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model (MM5) using both the traditional dynamic analysis approach and forecasts for a summertime period. The resultant meteorological fields are then used for emissions processing and air quality simulations using the Community Multiscale Air Quality Modeling System (CMAQ). The predictions of surface and near-surface meteorological fields and ozone are compared with a small network of collocated meteorological and air quality observations. Comparisons of 2-m temperature, 10-m wind speed, and surface shortwave radiation show a significant degradation over time when nudging is not used, whereas the dynamic analyses maintain consistent statistical scores over time for those fields. Using nudging in MM5 to generate dynamic analyses, on average, leads to a CMAQ simulation of hourly ozone with smaller error. Domainwide error patterns in specific meteorological fields do not directly or systematically translate into error patterns in ozone prediction at these sites, regardless of whether nudging is used in MM5, but large broad-scale errors in shortwave radiation prediction by MM5 directly affect ozone prediction by CMAQ at specific sites.

Dynamic Analysis and Structure Optimization of Linear Vibration Screen

2013 ◽  
Vol 364 ◽  
pp. 42-45
Author(s):  
Yong Yan Wang ◽  
Xiao Liang Liu ◽  
Wen Bin Wei ◽  
Nan Qin
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Dynamic Analysis ◽  
Center Of Mass ◽  
Structure Optimization ◽  
Element Model ◽  
Linear Vibration ◽  
Ansys Software ◽  
Structural Modifications ◽  
The Finite Element Model

Simulation of simplified the part structures of vibration screen by ANSYS software, and then establishes the finite element model of the linear vibration screen. Modal analysis and harmonic analysis of finite element model, and then according to the analysis results corresponding local structural modifications and adjust the center of mass of the modified vibration screen. Last verified the rationality of structure optimization.

Dynamic Force and Torque Analysis of a Spherical Four-Bar Mechanism

1995 ◽  
Author(s):  
J. R. Dooley
Keyword(s):  
Dynamic Analysis ◽  
Dynamic Force ◽  
Accurate Model ◽  
Dynamic Analyses ◽  
Torque Analysis

Abstract Spherical four-bar linkages are compact mechanisms capable of motion outside the plane and transmission between intersecting shafts. Dynamic analyses of spherical four-bar linkages are complicated by the fact that they are statically indeterminate. Previous solutions have used an RCCC approximation to model the 4R linkage. This paper extends previous results to include the material elasticity in the dynamic analysis. The results of this more accurate model are compared to those obtained from the RCCC model and it is shown that the RCCC approximation yields significant errors.

Stress Analysis on an Automotive Coil Spring Driven on Flat, Uphill, and Downhill Road Surfaces

2021 ◽  
Vol 892 ◽  
pp. 124-128
Author(s):  
Harahap Jagodang ◽  
Husaini ◽  
Edisah Putra Teuku ◽  
Dieter Schramm
Keyword(s):  
Carbon Steel ◽  
Dynamic Analysis ◽  
Stress Analysis ◽  
Maximum Stress ◽  
Road Surface ◽  
Coil Spring ◽  
Vehicle Load ◽  
Road Surfaces ◽  
Dynamic Analyses

This study aims to analyze the stress that occurred on the automotive coil spring made of SAE 5160 carbon steel due to various types of road surfaces. The 60-second strain signals measured on a coil spring of a car being driven on a flat, uphill, and downhill road surface were used as the loads in these dynamic analyses. The analysis results showed that the maximum stress occurred on the inside of the spring in the second coil from the top. The results of this dynamic analysis also showed that the three types of road surfaces provided almost the same stress. The downhill road surface gave the highest stress, which was 0.622 GPa, followed by flat road (0.621 GPa) and uphill road (0.62 GPa). The reasons for this are the shifting of the vehicle load to the front wheels together with the braking effect when driving downhill.

Dynamic Analysis of FRP-Reinforced Masonry Arches via a No-Tension Model with Damage

2014 ◽  
Vol 624 ◽  
pp. 619-626 ◽  
Author(s):  
Massimiliano Lucchesi ◽  
Barbara Pintucchi ◽  
Nicola Zani
Keyword(s):  
Dynamic Analysis ◽  
Beam Model ◽  
Normal Stresses ◽  
Masonry Arches ◽  
Irreversible Damage ◽  
Static And Dynamic Analysis ◽  
Reinforced Masonry ◽  
Composite Interface ◽  
Dynamic Analyses

A FE beam model to perform static and dynamic analysis of fiber-reinforced masonry arches is presented. Based on a constitutive equation formulated for no-tension masonry beams, the model accounts for a limit to the material deformability and provides for irreversible damage occurring under compression. In order to capture any possible FRP debonding, a procedure is also formulated to reduce the performance of the fiber when the tangential and normal stresses at the masonry-composite interface reach a critical value. Some dynamic analyses are performed on a case study with the aim of evaluating the effectiveness of FRP-retrofitting in improving seismic performances.

STABILITY AND DYNAMIC ANALYSIS OF COLD-FORMED STORAGE RACK STRUCTURES WITH SEMIRIGID CONNECTIONS

2011 ◽  
Vol 11 (06) ◽  
pp. 1059-1088 ◽  
Author(s):  
KESHAV K. SANGLE ◽  
KAMAL M. BAJORIA ◽  
RAJSHEKAR S. TALICOTTI
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
Buckling Analysis ◽  
Effective Length ◽  
Fundamental Period ◽  
Base Shear ◽  
Element Analysis ◽  
Semirigid Connections ◽  
Dynamic Analyses ◽  
The Impact

This paper presents the finite element buckling and dynamic analyses of two-dimensional (2D) single frames and three-dimensional (3D) frames of cold-formed sections with semirigid connections used in the conventional pallet racking system. The results of buckling analysis for the single 2D frames are compared with those from the experimental study and effective length approach given by RMI. The finite element model used for the single 2D plane frame is further extended to 3D frames with semirigid connections, for which the buckling analysis results are obtained. The buckling and dynamic analyses are carried out using ANSYS for 18 types of developed column sections. The stiffness of the semirigid connection is determined by both the single and double cantilever test methods, along with the nonlinear finite element analysis. Further, an equivalent single degree-of-freedom model is proposed for simulating the seismic behavior of the storage rack in the down-aisle direction, aimed at developing simplified equations for the fundamental period, base shear, and top displacement of the rack. A parametric study is carried out to compute the fundamental period and mode shape. The transient dynamic analysis is also performed for evaluating the impact of the forklift on columns of the frame.

scholarly journals Design and implementation of a tracer driver: Easy and efficient dynamic analyses of constraint logic programs

2008 ◽  
Vol 8 (5-6) ◽  
pp. 581-609
Author(s):  
LUDOVIC LANGEVINE ◽  
MIREILLE DUCASSÉ
Keyword(s):  
Dynamic Analysis ◽  
Low Cost ◽  
Logic Programs ◽  
Design And Implementation ◽  
On Demand ◽  
Front End ◽  
Analysis Tools ◽  
Dynamic Analyses ◽  
Constraint Logic Programs ◽  
High Level

AbstractTracers provide users with useful information about program executions. In this article, we propose a “tracer driver”. From a single tracer, it provides a powerful front-end enabling multiple dynamic analysis tools to be easily implemented, while limiting the overhead of the trace generation. The relevant execution events are specified by flexible event patterns and a large variety of trace data can be given either systematically or “on demand”. The proposed tracer driver has been designed in the context of constraint logic programming (CLP); experiments have been made within GNU-Prolog. Execution views provided by existing tools have been easily emulated with a negligible overhead. Experimental measures show that the flexibility and power of the described architecture lead to good performance. The tracer driver overhead is inversely proportional to the average time between two traced events. Whereas the principles of the tracer driver are independent of the traced programming language, it is best suited for high-level languages, such as CLP, where each traced execution event encompasses numerous low-level execution steps. Furthermore, CLP is especially hard to debug. The current environments do not provide all the useful dynamic analysis tools. They can significantly benefit from our tracer driver which enables dynamic analyses to be integrated at a very low cost.

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