Lebensdauer von Profilschienenführungen* – Teil 1/Lifespan of profile rail guides – Developing of a simplified rolling contact related life calculation for profile rail guides

2019 ◽  
Vol 109 (05) ◽  
pp. 370-376
Author(s):  
S. Ihlenfeldt ◽  
J. Müller ◽  
D. Staroszyk
Keyword(s):  
Mathematical Models ◽  
Life Span ◽  
Survival Probability ◽  
Mechanical Systems ◽  
Rolling Contact ◽  
Calculation Methods ◽  
Conventional Calculation ◽  
Mathematische Modelle ◽  
User Friendly

Die Berechnung der Lebensdauer von Profilschienenführungen (PSF) ist bei der Anlagenauslegung ein wesentlicher Bestandteil. Bei der wälzkontaktbezogenen Lebensdauerrechnung (WKBL) wird die Überlebenswahrscheinlichkeit jedes Wälzkontaktes berücksichtigt, was bei bestimmten Anordnungen von PSF, unter Momentenbelastung, bis zu 4-fach höhere Lebensdauerwerte als eine konventionelle Berechnung liefert. Neue mathematische Modelle erlauben eine adaptierbare und anwenderfreundliche Berechnung der WKBL.   Calculating the life span of profile rail guides is an essential part in designing new mechanical systems. The ‚rolling contact related life calculation‘ (RCRL) takes into account the survival probability of each rolling contact. This allows for calculating life spans up to four times higher than by conventional calculation methods for pitch and yaw moments on single profile rail guides. New mathematical models enable an adaptable and user-friendly calculation of RCRL.

scholarly journals Robot Modeling for Physical Rehabilitation

Robotics ◽  
2013 ◽  
pp. 1212-1232 ◽  
Author(s):  
Rogério Sales Gonçalves ◽  
João Carlos Mendes Carvalho
Keyword(s):  
Mathematical Models ◽  
Three Dimensional ◽  
Mechanical Systems ◽  
Industrial Robots ◽  
Limb Movements ◽  
Rehabilitation Robots ◽  
Wide Range ◽  
Movable Platform ◽  
Human Limb ◽  
Robot Modeling

The science of rehabilitation shows that repeated movements of human limbs can help the patient regain function in the injured limb. There are three types of mechanical systems used for movement rehabilitation: robots, cable-based manipulators, and exoskeletons. Industrial robots can be used because they provide a three-dimensional workspace with a wide range of flexibility to execute different trajectories, which are useful for motion rehabilitation. The cable-based manipulators consist of a movable platform and a base, which are connected by multiple cables that can extend or retract. The exoskeleton is fixed around the patient's limb to provide the physiotherapy movements. This chapter presents a summary of the principal human limb movements, a review of several mechanical systems used for rehabilitation, as well as common mathematical models of such systems.

Survival characteristics of the free-living cercarial population of the ectoparasitic digenean Transversotrema patialensis (Soparker, 1924)

Parasitology ◽  
1975 ◽  
Vol 70 (3) ◽  
pp. 295-310 ◽  
Author(s):  
R. M. Anderson ◽  
P. J. Whitfield
Keyword(s):  
Mathematical Models ◽  
Life Span ◽  
Conceptual Understanding ◽  
Biological Processes ◽  
Energy Reserves ◽  
Age Dependence ◽  
Maximum Life Span ◽  
Free Living ◽  
Age Dependent ◽  
Low Levels

The survival characteristics of free-living cercarial populations of Transversotrema patialensis were described and shown to be age-dependent. The maximum life-span was found to be 44 h with a 50% survival at 26 h. Activity and infectivity of the larvae were also characterized by age-dependence, and were demonstrated to be closely correlated with one another. For individual cercariae, both activity and infectivity had dropped to extremely low levels many hours before death occurred. An attempt was made to interrelate activity and infectivity, in a theoretical manner, with the availability of energy reserves.Conceptual understanding of the biological processes involved was aided by the formulation of simple mathematical models.

RESEARCH OF RELIABILITY AT THE DESIGN STAGE OF COMPLEX TECHNICAL SYSTEMS

2020 ◽  
pp. 1-20
Author(s):  
V. M. Trukhanov ◽  
S. S. Basova ◽  
G. V. Trukhanov ◽  
G. I. Kuprovskiy
Keyword(s):  
Mathematical Models ◽  
Present Article ◽  
Design Stage ◽  
Calculation Methods ◽  
Reliability Indices ◽  
Design Reliability ◽  
Complex Technical Systems ◽  
Technical Systems

The issues of nomenclature choice of reliability indices and methods of reliability distribution between components of product have been considered in the present article. Calculation methods of design reliability of expensive nondiscarding objects like movable mountings and also mathematical models of design reliability, which taking into account random and nonrandom failures. The technique of calculation and achievement of required level reliability has been represented.

Research and Analysis of Dynamic Behaviour in the Mathematical Models of the 6-Axle Locomotive

2011 ◽  
Vol 105-107 ◽  
pp. 541-544
Author(s):  
Van Tham Mai ◽  
Shi Jing Wu ◽  
Xiao Sun Wang ◽  
Jie Chen ◽  
S. A. K. S. Jafri
Keyword(s):  
Differential Equations ◽  
Mathematical Models ◽  
Dynamic Behavior ◽  
Dynamic Behaviour ◽  
Computer Software ◽  
Rolling Contact ◽  
Rolling Stock ◽  
Vertical Movements ◽  
Dynamic Behaviors ◽  
Second Order Differential Equations

With the aiming of mathematically modeling dynamic behavior in latitudinal and vertical movements of the 6-axle locomotive, this paper introduces the Kalker’s Wheel-Rail Rolling Contact Theories and their implementation in multibody codes. This paper also highlights methodology for solving inhomogeneous linear second-order differential equations with MATLAB computer software aided. The calculation has reported that the dynamic behaviors of Diesel-Electric 6-axle locomotive are significantly demonstrated. The calculation has reported that the dynamic behaviors of Diesel-Electric 6-axle locomotive are significantly demonstrated the requirements on Rolling stock Dynamic behaviors of Vietnam Railways.

scholarly journals An algorithm for discovering Lagrangians automatically from data

2015 ◽  
Vol 1 ◽  
pp. e31 ◽  
Author(s):  
Daniel J.A. Hills ◽  
Adrian M. Grütter ◽  
Jonathan J. Hudson
Keyword(s):  
Mathematical Models ◽  
Prior Knowledge ◽  
Model Building ◽  
Mechanical Systems ◽  
Future Evolution ◽  
Least Action ◽  
Building Process ◽  
Principle Of Least Action ◽  
Insight Into ◽  
Model Building Process

An activity fundamental to science is building mathematical models. These models are used to both predict the results of future experiments and gain insight into the structure of the system under study. We present an algorithm that automates the model building process in a scientifically principled way. The algorithm can take observed trajectories from a wide variety of mechanical systems and, without any other prior knowledge or tuning of parameters, predict the future evolution of the system. It does this by applying the principle of least action and searching for the simplest Lagrangian that describes the system’s behaviour. By generating this Lagrangian in a human interpretable form, it can also provide insight into the workings of the system.

scholarly journals Experimental and Numerical Study of Pressure Intensity in Detachable Joints of D Series Pumps

2021 ◽  
Vol 5 (2) ◽  
pp. 153-164
Author(s):  
Andrii Rudenko ◽  
Vladyslav Zubko ◽  
Viacheslav Khvorost ◽  
Andrii Lysenko
Keyword(s):  
Numerical Calculation ◽  
Mathematical Models ◽  
Numerical Study ◽  
Calculation Methods ◽  
Detachable Joint ◽  
Analysis Of Results ◽  
Accuracy Of Results ◽  
Object Of Study ◽  
Temperature Loads ◽  
Good Agreement

The object of study is a single-stage double-suction axially split volute casing centrifugal pump. Background. In the design process of pumps, the problems associated with ensuring the tightness of the axial joint of a pump casing being under the effect of mechanical and temperature loads, are being solved. During the study of axial joint tightness, numerical calculation methods are used to estimate the pressure intensity on the contacting surfaces. A detachable joint under the external load satisfies the criterions of the tightness if the pressure intensity on the sealing surfaces is higher than values of the specific pressure prescribed by regulations. However, inability to experimentally determine the pressure intensity on the contacting surfaces has so far prevented to assess the accuracy of results obtained by the numerical calculation methods. Objective. In order to verify the numerical results obtained by mathematical models, an experiment was carried out using a special Prescale film that registers the magnitude of the contact pressure on the joint of the specimen model of the flange fragment. Based on the experimental results, an analysis of the pressure intensity distribution was conducted. Methods. To conduct the experiment, there was developed a method for determining the pressure intensity on the contacting surfaces according to the proposed scheme of the specimen of the flange fragment. Results. A comparative analysis of the solving results obtained for the contact problem on the finite-element models of the flange fragment and the zone of the pump casing joint in the discharge chamber area showed a good coincidence of the results. Analysis of results obtained experimentally on the specimen of flange fragment and results of the numerical calculation on the flange fragment model also showed a good agreement. Conclusions. Therefore, results of the calculation of the pressure intensity in the detachable joints on mathematical models have been experimentally confirmed.

Membrane Micro Electro-Mechanical Systems for Industrial Applications

2020 ◽  
pp. 139-175
Author(s):  
Mario Versaci ◽  
Francesco Carlo Morabito
Keyword(s):  
Mathematical Models ◽  
Closed Form ◽  
Numerical Solutions ◽  
Mechanical Systems ◽  
Industrial Applications ◽  
Micro Electro Mechanical Systems ◽  
Curves And Surfaces ◽  
Uniqueness Of The Solution ◽  
Numerical Tools ◽  
Membrane Deflection

The objective of this chapter is to provide the analytical-numerical tools for the simplified rewriting of the most important mathematical models of MEMS membrane devices for Mechatronics, exploiting advanced concepts and results in the theory of curves and surfaces. Moreover, when the solution in closed form could not be obtained (that is, it is impossible to obtain the membrane deflection analytically), some consolidated techniques will be described both to obtain conditions ensuring existence/uniqueness of the solution, and the most suitable approaches for obtaining numerical solutions in the absence of ghost solutions. Finally, some practical examples will illustrate the approaches presented.

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