Time-efficient Simulation of Surface-excited Guided Lamb Wave Propagation in Composites

Time-efficient Simulation of Surface-excited Guided Lamb Wave Propagation in Composites
Author: Alexander Karmazin
Publisher: KIT Scientific Publishing
Total Pages: 222
Release: 2014-05-22
Genre: Science
ISBN: 3866449356

The methods of time-efficient simulation of surface-excited wave propagation in plate-like multilayered composites are presented. The mathematical model of wave propagation in laminated plate based on the elasticity theory is transformed and then solved in wavenumber-frequency domain. The numerical methods for computation of inverse transform in time-space domain are developed and used for analysis of wave and energy propagation phenomena occurring in composite plates due to surface excitation.

An efficient solution procedure for elastohydrodynamic contact problems considering structural dynamics

An efficient solution procedure for elastohydrodynamic contact problems considering structural dynamics
Author: Schmidt, Jan Henrik
Publisher: KIT Scientific Publishing
Total Pages: 164
Release: 2019-01-14
Genre: Structural dynamics
ISBN: 3731508729

This work presents an efficient solution procedure for the elastohydrodynamic (EHD) contact problem considering structural dynamics. The contact bodies are modeled using reduced finite element models. Singly diagonal implicit Runge-Kutta (SDIRK) methods are used for adaptive time integration. The structural model is coupled with the nonlinear Reynolds Equation using a monolithic coupling approach. Finally, a reduced order model of the complete nonlinear coupled problem is constructed.

Crosswind stability of vehicles under nonstationary wind excitation

Crosswind stability of vehicles under nonstationary wind excitation
Author: Zhang, Xiaoyu
Publisher: KIT Scientific Publishing
Total Pages: 218
Release: 2015-05-13
Genre: Technology (General)
ISBN: 373150376X

This work has studied the crosswind stability of vehicles under nonstationary wind excitation in various scenarios. Railway vehicles running on curved and straight track with varying vehicle speed are studied. Road vehicles are classified into different categories. For each vehicle class, a corresponding worst-case vehicle model has been built. As the wind excitation on the vehicle is a stochastic process, a risk analysis has to be carried out and failure probabilities are computed and analyzed.

Lubricant transport towards tribocontact in capillary surface structures

Lubricant transport towards tribocontact in capillary surface structures
Author: Klima, Joachim
Publisher: KIT Scientific Publishing
Total Pages: 206
Release: 2018-11-13
Genre:
ISBN: 3731508141

To counter lubricant shortage at a frictional contact (starvation), lubrication liquids, e.g. oils, are actively transported from a distant location towards the undersupplied tribocontact. This is done via small channels or generally via structures cut into a flat surface. In this way one can use capillary force as a cheap and reliable driver of the lubricant flow. Numerical modeling and experiments show that this method can be considered a promising new option to enhance tribocontact operation.

Advanced Materials

Advanced Materials
Author: Ivan A. Parinov
Publisher: Springer
Total Pages: 620
Release: 2017-08-04
Genre: Technology & Engineering
ISBN: 331956062X

This book presents 50 selected peer-reviewed reports from the 2016 International Conference on “Physics and Mechanics of New Materials and Their Applications”, PHENMA 2016 (Surabaya, Indonesia, 19–22 July, 2016). The Proceedings are devoted to processing techniques, physics, mechanics, and applications of advanced materials. As such, they examine a wide spectrum of nanostructures, ferroelectric crystals, materials and composites, as well as other promising materials with special properties. They present nanotechnology approaches, modern environmentally friendly piezoelectric and ferromagnetic techniques, and physical and mechanical studies of the structural and physical-mechanical properties of the materials discussed. Further, a broad range of original mathematical and numerical methods is applied to solve various technological, mechanical and physical problems, which are inte resting for applications. Great attention is devoted to novel devices with high accuracy, longevity and extended possibilities to work in wide temperature and pressure ranges, aggressive media, etc., which show improved characteristics, defined by the developed materials and composites, opening new possibilities to study different physico-mechanical processes and phenomena.

Advanced Materials

Advanced Materials
Author: Shun-Hsyung Chang
Publisher: Springer Science & Business Media
Total Pages: 378
Release: 2014-03-25
Genre: Technology & Engineering
ISBN: 3319037498

Advanced materials are the basis of modern science and technology. This proceedings volume presents a broad spectrum of studies of novel materials covering their processing techniques, physics, mechanics, and applications. The book is concentrated on nanostructures, ferroelectric crystals, materials and composites, materials for solar cells and also polymeric composites. Nanotechnology approaches, modern piezoelectric techniques and also latest achievements in materials science, condensed matter physics, mechanics of deformable solids and numerical methods are presented. Great attention is devoted to novel devices with high accuracy, longevity and extended possibilities to work in wide temperature and pressure ranges, aggressive media etc. The characteristics of materials and composites with improved properties opening new possibilities of various physical processes, in particular transmission and receipt of signals under water, are described.

Modeling and simulation of porous journal bearings in multibody systems

Modeling and simulation of porous journal bearings in multibody systems
Author: Buuren, Sietze van
Publisher: KIT Scientific Publishing
Total Pages: 182
Release: 2014-07-30
Genre: Technology & Engineering
ISBN: 3731500841

A specific cost-efficient type of plain journal bearing is the porous journal bearing, which possesses a pervious bush that serves as a lubricant reservoir. The current work is concerned with modeling porous journal bearings in multibody systems, for which dynamical models are needed to investigate the bearing's behavior. Such porous journal bearing models as well as models of elementary rotor-bearing systems including these, were developed and investigated during the course for this work.

Dynamics of Rotors on Refrigerant-Lubricated Gas Foil Bearings

Dynamics of Rotors on Refrigerant-Lubricated Gas Foil Bearings
Author: Leister, Tim
Publisher: KIT Scientific Publishing
Total Pages: 192
Release: 2021-10-28
Genre: Technology & Engineering
ISBN: 3731511126

The gas foil bearing (GFB) technology is a key factor for the transition to oil-free rotating machinery. Among numerous advantages, GFBs offer the unique ability to be lubricated with working fluids such as refrigerants. However, the computational analysis of refrigerant-lubricated GFB–rotor systems represents an interdisciplinary problem of enormous complexity. This work pushes forward existing limits of feasibility and establishes a new strategy that enables stability and bifurcation analyses.

On direct and inverse problems related to longitudinal impact of non-uniform elastic rods

On direct and inverse problems related to longitudinal impact of non-uniform elastic rods
Author: Burgert, Jens
Publisher: KIT Scientific Publishing
Total Pages: 122
Release: 2021-05-07
Genre: Technology & Engineering
ISBN: 3731510871

The impact of two non-uniform elastic rods is considered and a recursive method was developed that solves the inverse problem: Find the location-dependent impedance function of the impacting rod that generates a prescribed impact force. The developed method delivers exact solutions in closed-form. Moreover, a condition is derived which states if a physically meaningful solution exists. Finally, the underlying 1D model has been validated experimentally.

On the Influence of Piecewise Defined Contact Geometries on Friction Dampers

On the Influence of Piecewise Defined Contact Geometries on Friction Dampers
Author: Aramendiz Fuentes, Jimmy Alberto
Publisher: KIT Scientific Publishing
Total Pages: 180
Release: 2023-09-12
Genre:
ISBN: 373151267X

This work considers dampers that do not solely focus on a single strategy but instead combine them. The capabilities of conventional dry friction dampers are expanded by taking into account piecewise defined contact geometries. This leads to friction dampers that change their behavior depending on the amplitude of the oscillations. The vibration damping device in this work, introduces damping at high oscillation amplitudes and takes advantage of absorption at low oscillation amplitudes.