scholarly journals Finite Element Analysis of Viscoelastic Nanofluid Flow with Energy Dissipation and Internal Heat Source/Sink Effects

2016 ◽  
Vol 3 (2) ◽  
pp. 1421-1447 ◽  
Author(s):  
P. Rana ◽  
R. Bhargava ◽  
O. Anwar Bég ◽  
A. Kadir
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Energy Dissipation ◽  
Heat Source ◽  
Internal Heat ◽  
Internal Heat Source ◽  
Nanofluid Flow ◽  
Element Analysis ◽  
Viscoelastic Nanofluid ◽  
Source Sink

Hysteresis Heating of Railroad Bearing Thermoplastic Elastomer Suspension Element

2017 ◽  
Author(s):  
Oscar O. Rodriguez ◽  
Arturo A. Fuentes ◽  
Constantine Tarawneh ◽  
Robert E. Jones
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Steady State ◽  
Temperature Distribution ◽  
Heat Generation ◽  
Internal Heat ◽  
Thermoplastic Elastomer ◽  
Internal Heat Generation ◽  
Element Analysis ◽  
Railroad Bearing

Thermoplastic elastomers (TPE’s) are increasingly being used in rail service in load damping applications. They are superior to traditional elastomers primarily in their ease of fabrication. Like traditional elastomers they offer benefits including reduction in noise emissions and improved wear resistance in metal components that are in contact with such parts in the railcar suspension system. However, viscoelastic materials, such as the railroad bearing thermoplastic elastomer suspension element (or elastomeric pad), are known to develop self-heating (hysteresis) under cyclic loading, which can lead to undesirable consequences. Quantifying the hysteresis heating of the pad during operation is therefore essential to predict its dynamic response and structural integrity, as well as, to predict and understand the heat transfer paths from bearings into the truck assembly and other contacting components. This study investigates the internal heat generation in the suspension pad and its impact on the complete bearing assembly dynamics and thermal profile. Specifically, this paper presents an experimentally validated finite element thermal model of the elastomeric pad and its internal heat generation. The steady-state and transient-state temperature profiles produced by hysteresis heating of the elastomer pad are developed through a series of experiments and finite element analysis. The hysteresis heating is induced by the internal heat generation, which is a function of the loss modulus, strain, and frequency. Based on previous experimental studies, estimations of internally generated heat were obtained. The calculations show that the internal heat generation is impacted by temperature and frequency. At higher frequencies, the internally generated heat is significantly greater compared to lower frequencies, and at higher temperatures, the internally generated heat is significantly less compared to lower temperatures. However, during service operation, exposure of the suspension pad to higher loading frequencies above 10 Hz is less likely to occur. Therefore, internal heat generation values that have a significant impact on the suspension pad steady-state temperature are less likely to be reached. The commercial software package ALGOR 20.3TM is used to conduct the thermal finite element analysis. Different internal heating scenarios are simulated with the purpose of obtaining the bearing suspension element temperature distribution during normal and abnormal conditions. The results presented in this paper can be used in the future to acquire temperature distribution maps of complete bearing assemblies in service conditions and enable a refined model for the evolution of bearing temperature during operation.

COMPUTATIONAL INVESTIGATION OF ENERGY DISSIPATION THROUGH PROGRESSIVE FAILURE IN TAILORED COMPOSITE STRUCTURES VIA EXPLICIT FINITE ELEMENT ANALYSIS

2021 ◽  
Author(s):  
ANIRUDH SRINIVAS ◽  
D. STEFAN DANCILA
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Composite Material ◽  
Energy Dissipation ◽  
Progressive Failure ◽  
Tensile Loading ◽  
Stress Wave Propagation ◽  
Element Analysis ◽  
Explicit Finite Element ◽  
Explicit Finite Element Analysis

A composite material tailoring concept for progressive failure under tensile loading has been previously developed, modeled, and experimentally validated by the second author and his collaborators. The concept relies upon a sequential failure process induced in a structure of series connection of parallel redundant load path elements of tailored length and strength. The resulting yield-type response under tensile loading is characterized by an increased energy dissipation compared to a reference conventional structural element of nominally identical length and crosssectional area, and of the same composite material. In this work, this composite tailoring concept is computationally investigated for IM7-8552 composite material using a dynamic, explicit finite element analysis in Abaqus. The approach offers the advantage of capturing the stress wave propagation within the model throughout the dynamic failure sequence, thereby providing a better understanding of the failure progression and the energy dissipation mechanisms at work. In this study, progressive failure of the tailored composite structure is modeled and analyzed for different configurations of lengths and widths. Model predictions are illustrated for and compared with selected tailoring configurations from the literature. Developing an explicit finite element approach for analyzing the tailoring concept opens the door to characterizing a wide variety of related, more complex configurations for which analytical solutions do not yet exist or may not even be feasible, and/or for which experimental results may be difficult or overly expensive to obtain.

Sign in / Sign up

Export Citation Format

Share Document