scholarly journals Coupled effect of loading frequency and amplitude on the fatigue behavior of advanced sheet molding compound (A-SMC)

2016 ◽  
Vol 36 (4) ◽  
pp. 271-282 ◽  
Author(s):  
M Shirinbayan ◽  
J Fitoussi ◽  
F Meraghni ◽  
B Surowiec ◽  
M Laribi ◽  
...  
Keyword(s):  
Fatigue Tests ◽  
The Self ◽  
Tension Stress ◽  
Loading Frequency ◽  
Compound A ◽  
Molding Compound ◽  
Sheet Molding Compound ◽  
Self Heating ◽  
Coupled Effect ◽  
The Matrix

This paper presents the experimental results of tension-tension stress-controlled fatigue tests performed on advanced sheet molding compound (A-SMC). It aims at analyzing the effect of fiber orientation, loading amplitude, and frequency on the fatigue response and the related temperature evolution due to the self-heating phenomenon. Two types of A-SMC have been analyzed: randomly oriented (RO) and highly oriented (HO). The coupled effect of the loading amplitude and the frequency has been studied. It has been shown that the couple frequency-amplitude affects the nature of the fatigue overall response which can be governed by the damage mechanisms accumulation (mechanical fatigue) and/or by the self-heating (induced thermal fatigue). For fatigue loading at 100 Hz, self-heating has been observed and yielded to a temperature rise up to 70℃. The latter causes a decrease of the storage modulus related to the β-transition of the vinylester. It has been demonstrated that the self-heating produced a material softening and decreased the fatigue life. SEM observations revealed that the samples tested at 100 Hz, exhibit smooth debonding surfaces due to the induced thermal softening of the matrix whereas more brittle fracture of the matrix surrounding fibers is observed during the fatigue tests achieved at 10 Hz.

scholarly journals High strain rate visco-damageable behavior of Advanced Sheet Molding Compound (A-SMC) under tension

2015 ◽  
Vol 82 ◽  
pp. 30-41 ◽  
Author(s):  
M. Shirinbayan ◽  
J. Fitoussi ◽  
F. Meraghni ◽  
B. Surowiec ◽  
M. Bocquet ◽  
...  
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Compound A ◽  
Molding Compound ◽  
Sheet Molding Compound

scholarly journals Numerical studies on the heat dissipation process in elastomers under rotating loading direction

2021 ◽  
Author(s):  
M. Abdelmoniem ◽  
B. Yagimli
Keyword(s):  
Heat Dissipation ◽  
Viscoelastic Model ◽  
Material Model ◽  
Fatigue Tests ◽  
Shear Loading ◽  
The Self ◽  
Self Heating ◽  
Applied Loading ◽  
User Subroutine ◽  
Numerical Studies

AbstractElastomeric components such as car bearings and vibration dampers are subjected to dynamic loads with various amplitudes and loading directions during operation. To better understand the lifetime expectancy of these components it is required to implement a material model that sufficiently accounts for the material thermo-mechanical behaviour. This paper implements a finite viscoelastic model which includes heat dissipation and addresses the effect of inelasticity on the self-heating and the applied loading conditions. The material model is implemented in a user subroutine and finite element calculations are carried out on a simple shear loading with rotating directions. The self-heating effect and the resulting variation of the dissipation induced forces are shown and discussed. With the aid of the presented material model, thermo-mechanically coupled simulations can be performed. Based on the results, the required loading limits and boundary conditions for the mechanical fatigue tests can be defined to minimise the thermal fatigue effects.

Synergistic Effect on Flexural Properties of Kenaf-Glass Hybrid Composite

2012 ◽  
Vol 626 ◽  
pp. 989-992 ◽  
Author(s):  
Atiqah Afdzaluddin ◽  
Md Abdul Maleque ◽  
Mohammed Iqbal
Keyword(s):  
Synergistic Effect ◽  
Hybrid Composite ◽  
Volume Fraction ◽  
Unsaturated Polyester ◽  
Glass Fibers ◽  
Flexural Properties ◽  
Molding Compound ◽  
Sheet Molding Compound ◽  
Structural Applications ◽  
The Matrix

This paper presents the synergistic effect on flexural properties of kenaf-glass (KG) mat reinforced unsaturated polyester (UPE) hybrid composite which can compounded using sheet molding compound (SMC) process. The matrix is kept constant with 70 % volume fraction while kenaf and glass fibers were varied, such as 7.5/22.5 v/v, 15/15 v/v and 22.5/7.5 v/v. The 30 % kenaf and 30 % glass are also used for the preparation of composite materials. The kenaf mat was treated with 6% sodium hydroxide (NaOH) diluted solution for 3 hours. This mercerization process improved the interface by interacting with both the fiber and its matrix. The flexural test was performed using ASTM D790-03 standard. The study showed with the addition of kenaf and glass mat 15/15 v/v, the optimum flexural properties was obtained compared to other composition. This can be concluded that 15/15 v/v KG mat reinforced unsaturated polyester hybrid composite is the most appropriate hybrid composite which can be considered for many engineering structural applications mainly in automotive panel, bottom structure and bumper beam.

scholarly journals Critical Frequency of Self-Heating in a Superelastic Ni-Ti Belleville Spring: Experimental Characterization and Numerical Simulation

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7140
Author(s):  
Emmanuel Ferreira de Souza ◽  
Paulo César Sales da Silva ◽  
Estephanie Nobre Dantas Grassi ◽  
Carlos José de Araújo ◽  
Antonio Gilson Barbosa de Lima
Keyword(s):  
Critical Frequency ◽  
Testing Machine ◽  
The Self ◽  
Experimental Methodology ◽  
Cyclic Behavior ◽  
Damping Factor ◽  
Loading Frequency ◽  
Heat Accumulation ◽  
Average Temperature ◽  
Self Heating

The mechanical loading frequency affects the functional properties of shape memory alloys (SMA). Thus, it is crucial to study its effect for the successful use of these materials in dynamic applications. Based on the superelastic cyclic behavior, this work presents an experimental methodology for the determination of the critical frequency of the self-heating of a NiTi Belleville conical spring. For this, cyclic compressive tests were carried out using a universal testing machine with loading frequencies ranging from 0.5 Hz to 10 Hz. The temperature variation during the cyclic tests was monitored using a micro thermocouple glued to the NiTi Belleville spring. Numerical simulations of the spring under quasi-static loadings were performed to assist the analysis. From the experimental methodology applied to the Belleville spring, a self-heating frequency of 1.7 Hz was identified. The self-heating is caused by the latent heat accumulation generated by successive cycles of stress-induced phase transformation in the material. At 2.0 Hz, an increase of 1.2 °C in the average temperature of the SMA device was verified between 1st and 128th superelastic cycles. At 10 Hz, the average temperature increase reached 7.9 °C and caused a 10% increase in the stiffness and 25% decrease in the viscous damping factor. Finally, predicted results of the force as a function of the loading frequency were obtained.

scholarly journals Micromechanical Modelling of Dynamic Behavior of Advanced Sheet Molding Compound (A-SMC) Composite

2020 ◽  
Vol 27 (3) ◽  
pp. 321-335 ◽  
Author(s):  
H. Ayari ◽  
M. Shirinbayan ◽  
A. Imaddahen ◽  
S. Tamboura ◽  
H. Ben Daly ◽  
...  
Keyword(s):  
Dynamic Behavior ◽  
Compound A ◽  
Molding Compound ◽  
Micromechanical Modelling ◽  
Sheet Molding Compound

Numerical modelling of the self-heating process of a wet porous medium

2011 ◽  
Vol 54 (25-26) ◽  
pp. 5200-5206 ◽  
Author(s):  
A. Ejlali ◽  
D.J. Mee ◽  
K. Hooman ◽  
B.B. Beamish
Keyword(s):  
Porous Medium ◽  
Numerical Modelling ◽  
The Self ◽  
Heating Process ◽  
Self Heating
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