Numerical and Experimental Study of a Crash Absorption Keel

2007 ◽  
Vol 348-349 ◽  
pp. 953-956
Author(s):  
Chiara Colombo ◽  
Laura Vergani ◽  
Nino Ascone Modica
Keyword(s):  
Finite Element Method ◽  
Experimental Study ◽  
Experimental Studies ◽  
The Finite Element Method ◽  
State Of Stress ◽  
Design Analyses ◽  
The Impact ◽  
Sailing Boat ◽  
System Geometry ◽  
Made In

Aim of this paper is to study the impact between the sailing boat keel and the ground and to look for the optimal configuration of the bulb-keel-hull system able to direct the damage in the bulb-keel zone avoiding the hull region. The research, which is carried out in collaboration with Wally shipyard, requires firstly an accurate investigation of the bulb-keel-hull system geometry, of the boat inertial properties and of the impact condition. Secondly, a numerical dynamic analysis by means of the finite element method allows to model the impact and to determine how, during the collision, the state of stress varies and how the kinetic energy is absorbed/dissipated. Starting from these results, the performance of the present configuration is evaluated in several conditions and some proposals for new design configuration are made. In particular the results carried out from the new design analyses were evaluated comparing themselves to results obtained from experimental studies.

scholarly journals Simulation of the impact resistance of Kilo type submarine loaded with non-contact mine explosion

2017 ◽  
pp. 99-110
Author(s):  
Bogdan Szturomski ◽  
Radosław Kiciński
Keyword(s):  
Finite Element Method ◽  
Pressure Wave ◽  
Impact Resistance ◽  
Acoustic Medium ◽  
The Finite Element Method ◽  
State Of Stress ◽  
Stress And Deformation ◽  
Submarine Hull ◽  
Explosion Load ◽  
The Impact

The paper presents simulations of the state of stress and deformation of the Kilo class submarine hull loaded from pressure wave of non-contact mine explosion. To accomplish the task the finite element method was used. Pressure wave was described by T. L. Geers’a and K. S. Hunter model. The way of modeling the pressure wave using the acoustic medium implemented to CAE programs was shown. To describe the material an elastic-plastic model of Jonson-Cook which takes into account the speed of deformation was used. The paper presents pressure distribution on the Kilo type submarine hull exposed on 100 kg of TNT explosion load in front of the bow of the ship.

Research of throwing areols of underground pipeline in permafrost

2021 ◽  
pp. 21-30
Author(s):  
T. S. Sultanmagomedov ◽  
◽  
R. N. Bakhtizin ◽  
S. M. Sultanmagomedov ◽  
T. M. Halikov ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Experimental Study ◽  
Finite Element ◽  
Strain State ◽  
Operating Temperature ◽  
Operating Conditions ◽  
Loss Of Stability ◽  
Underground Pipeline ◽  
The Finite Element Method ◽  
Permafrost Thawing

Study is due to the possibility of loss of stability of the pipeline in the process of pumping a product with a positive operating temperature and the formation of thawing halos. The article presents the ways of solving the thermomechanical problem of pipeline displacement due to thawing. The rate of formation of a thawing halo is investigated depending on the initial temperatures of the soil and the pumped product. The developed monitoring system makes it possible to study the rate of occurrence of thawing halos in the process of pumping the product. An experimental study on the formation of thawing halos around the pipeline was carried out on an experimental model. A thermophysical comparative calculation of temperatures around the pipeline on a model by the finite element method has been carried out. Keywords: underground pipeline; permafrost; thawing halo; monitoring; operating conditions; stress–strain state.

scholarly journals Experimental Study of the Chaotic Jerk Circuit Application for Chaos Shift Keying

2021 ◽  
Vol 58 (4) ◽  
pp. 55-68
Author(s):  
F. Capligins ◽  
A. Litvinenko ◽  
A. Aboltins ◽  
E. Austrums ◽  
A. Rusins ◽  
...  
Keyword(s):  
Experimental Study ◽  
Voltage Drop ◽  
Experimental Studies ◽  
Chaotic Synchronization ◽  
Channel Noise ◽  
Error Feedback ◽  
Shift Keying ◽  
The Stability ◽  
Chaos Shift Keying ◽  
The Impact

Abstract The paper presents a study of the chaotic jerk circuit (CJC) employment capabilities for digital communications. The concept of coherent chaos shift keying (CSK) communication system with controlled error feedback chaotic synchronization is proposed for a specific CJC in two modifications. The stability of chaotic synchronization between the two CJCs was evaluated in terms of voltage drop at the input of the slave circuit and the impact of channel noise using simulations and experimental studies.

scholarly journals ANÁLISE NUMÉRICA DE PERFIS DE AÇO FORMADOS A FRIO EM SEÇÃO “I” CONSTITUÍDA POR DUPLO “U” SUBMETIDOS À COMPRESSÃO

2020 ◽  
Vol 12 (1) ◽  
pp. 95-110
Author(s):  
Gabriel Cintra Macedo ◽  
Wanderson Fernando Maia
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Plate Thickness ◽  
Experimental Studies ◽  
Structural Behavior ◽  
The Finite Element Method ◽  
Geometric Imperfections ◽  
Initial Geometric Imperfections ◽  
Normal Strength ◽  
Double Channel

Although the section “I”, in double channel, is widely used, there are few studies on its behavior. Therefore, this work aims to contribute to a greater mastery over the structural behavior of this built-up sections. A nonlinear numerical analysis was performed using the Finite Element Method in the Ansys program, using existing experimental studies as a comparative database. The effect of length, number of connections, plate thickness and the presence of geometric and material imperfections on the normal strength of the columns. For this analysis, it was essential to consider the initial geometric imperfections, because there was a considerable reduction in the normal strength of the columns, thus getting closer to the values obtained experimentally. With regard to normative procedures, values against security were found in most cases, showing the need to conduct further studies in the area for the development of more appropriate formulations.

scholarly journals An Experimental Study to Evaluate the Impact of the Programming Paradigm in the Testing Activity

2012 ◽  
Vol 15 (1) ◽  
Author(s):  
Simone de Rocio Senger de Souza ◽  
Marllos Paiva Prado ◽  
Ellen Francine Barbosa ◽  
José Carlos Maldonado
Keyword(s):  
Experimental Study ◽  
Experimental Studies ◽  
Programming Paradigm ◽  
Time Restrictions ◽  
Activity Cost ◽  
The Cost ◽  
Programming Paradigms ◽  
The Impact ◽  
Initial Results ◽  
Testing Criteria

Several techniques and criteria are available to help conducting testing activity. The choice for one of them depends on different aspects, such as the time restrictions, ef- fectiveness of the testing criteria or the features of the program under test. In this context, the programming paradigm might influence in the testing activity cost. This paper presents the results of an experimental study to characterize and evaluate the cost and strength of structural and functional testing criteria, comparing object-oriented and procedural programming paradigms. A set of 32 programs from the data structure do- main was considered in this study. The main goals in the execution of this research were: i) to obtain initial results about the investigated questions; ii) to generate artifacts which can be used as basis to define and conduct further experimental studies; iii) to support training and teaching of software testing activity.

scholarly journals Selected aspects of numerical modelling in prediction of building vibrations due to traffic

2018 ◽  
Vol 196 ◽  
pp. 01055
Author(s):  
Sławomir Dudziak ◽  
Zofia Kozyra
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Modelling ◽  
The Finite Element Method ◽  
Frequency Range ◽  
Mass Estimation ◽  
Structure Response ◽  
Dynamic Analyses ◽  
Transportation Routes ◽  
The Impact

Dynamic analyses play an important role in the process of designing buildings in the vicinity of transportation routes. The Finite Element Method is the most popular modelling technique, because it allows to simulate the structure response in the higher frequency range properly. However, the results of such analyses depend on many factors and can differ a lot. This paper discusses the impact of the building mass estimation and neglecting or including damping in the analysis on the assessment of influence of vibrations due to traffic on people.

A Discussion on natural strain and geological structure - The finite element method and the solution of some geophysical problems

1976 ◽  
Vol 283 (1312) ◽  
pp. 139-151 ◽  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Geological Structure ◽  
The Finite Element Method ◽  
Recent Developments ◽  
Limited Application ◽  
Discrete Problems ◽  
The Finite Difference Method ◽  
Made In ◽  
Element Method

The finite element method has become established as a powerful tool for the solution of many problems of continuum mechanics where its physical interpretation, by analogy with discrete problems of structural analysis permits the user to exercise a considerable degree of insight and judgement in its use. Further it is now a recognized mathematical procedure of approximation which embraces many older methodologies (such as the finite difference method) as a subclass. In the field of geological studies its impact is fairly recent and only a limited application has been made to date. The techniques used here have been limited to those established over a decade ago in the parallel fields and recent developments and possibilities barely touched upon. In this paper the author therefore attempts to ( a ) outline some of the general mathematical and practical aspects of the method with illustrations from various fields which are relevant to geological problems, ( b ) survey accomplishments already made in geology and geotechnical fields, and ( c ) suggest some possible new extensions of application.

An Ultrasonic Knife System for MEMS Packaging

2012 ◽  
Vol 190-191 ◽  
pp. 23-27
Author(s):  
Jin Sha ◽  
Zhi Yuan Yao ◽  
Yang Jiao
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
High Temperature ◽  
High Frequency ◽  
Ultrasonic Transducer ◽  
The Finite Element Method ◽  
Structure Amplitude ◽  
High Frequency Vibration ◽  
Mems Packaging ◽  
The Impact

This paper proposes an ultrasonic knife system for MEMS packaging. The ultrasonic knife system is consisted of an ultrasonic transducer, a cutter and a gripper feeder. The ultrasonic transducer engenders high frequency vibration, which lead to the resonance of the structure. Amplitude transformer can magnify the amplitude. By the impact and collision of the cutter, the material can be cut through, and the high temperature created by high-frequency vibration can do the welding. The structure is designed and optimized by the finite element method, and a model machine is produced. According to the experimental results, the ultrasonic knife system has the virtues of high cutting force and better wedding feature, which are suitable for MEMS packaging.

Bridge Surface Roughness Identified from the Displacement Influence Lines of the Contact Points by Two Connected Vehicles

2020 ◽  
pp. 2043003
Author(s):  
Y. B. Yang ◽  
B. Q. Wang ◽  
Z. L. Wang ◽  
K. Shi ◽  
H. Xu ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Surface Roughness ◽  
Dynamic Properties ◽  
Surface Profile ◽  
Connected Vehicles ◽  
The Finite Element Method ◽  
Contact Points ◽  
Continuous Beams ◽  
Static Correlation ◽  
The Impact

In this study, a new, effective procedure is proposed for identifying the surface roughness from the responses recorded of two connected test vehicles moving over the bridge. Central to this study is the proposal of a simple static correlation formula for relating the dynamic deflections of the two vehicles’s contact points on the bridge, via the displacement influence lines (DILs). With the aid of this relation, the roughness formula for estimating the bridge surface profile is derived using the responses of the leading and following vehicles. It does not require any prior knowledge of the dynamic properties of the bridge. The efficacy of the proposed procedure is validated for both the simple and three-span continuous beams by the finite element method (FEM). Also, a parametric study is conducted for various physical properties of the test vehicles. It is confirmed that the roughness profiles back-calculated from the proposed formula agree excellently with the assumed ones for both the simple and continuous beams. For use in practice, the two connected test vehicles should not be designed too heavy and not to move at too fast speeds, in order to reduce the impact on the bridge.

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