Static and dynamic mechanical properties of warm mixed asphalt mixture before and after aging

Truck Tire Thermal-Mechanical FEA and DMA with Application to Endurance Evaluation4

Tire Science and Technology ◽

10.2346/1.2345651 ◽

2006 ◽

Vol 34 (4) ◽

pp. 220-236 ◽

Cited By ~ 7

Author(s):

H. S. Yin ◽

Y. S. Hu ◽

H. Zhang ◽

M. M. Yang ◽

Y. T. Wei

Keyword(s):

Mechanical Properties ◽

Dynamic Mechanical Properties ◽

Element Analysis ◽

Dynamic Mechanical ◽

Simulation Techniques ◽

Changing Trends ◽

Truck Tire ◽

Steady State Temperature ◽

Before And After ◽

Endurance Tests

Abstract This work presents a thermal-mechanical finite element analysis (FEA) of a typical heavy-duty radial truck tire on both drum and roadway. The calculated footprint pressures, strain energy density, and steady-state temperature distribution are compared between two cases. In addition to structural and thermal simulation techniques for obtaining stress, strain, and temperature distributions in the tire key areas, several material analysis techniques are also used to characterize the tire rubber materials. Temperature, frequency, and strain scan tests are conducted to obtain the dynamic mechanical properties of the tire rubbers of interest. Furthermore, the changes of the materials’ dynamic mechanical properties with fatigue have been investigated by testing tire materials before and after drum endurance tests. It has been found that different parts show different changing trends in dynamical properties after endurance tests, which might indicate different failure mechanisms. Combining the materials’ characterization techniques and thermal-mechanical FEA, this paper attempts to evaluate the tire shoulder failure mechanism and predict the relative shoulder endurance of an 11.00R20 truck tire.

Get full-text (via PubEx)

Research on Fractional Derivative Viscoelastic Constitutive Relation of Asphalt Mixture

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.446-449.2560 ◽

2012 ◽

Vol 446-449 ◽

pp. 2560-2566

Author(s):

Hua Yin ◽

Yi Li ◽

Nai Zhou Wang

Keyword(s):

Mechanical Properties ◽

Fractional Derivative ◽

Phase Angle ◽

Constitutive Relation ◽

Viscoelastic Model ◽

Asphalt Mixture ◽

Maxwell Model ◽

Dynamic Mechanical Properties ◽

Dynamic Mechanical ◽

Definition Of

Based on the definition of fractional derivative, the paper proposed a unique new idea to describe the viscoelastic property of asphalt mixture with fractional calculus. According to the SPT (Simple Performance Tests) test results, the dynamic modulus and phase angle of asphalt mixture were determined. The result of the test was fitted with the classical Kelvin model, the Maxwell model, the solid model with three elements, respectively. It showed that the classical viscoelastic model did not simulate the dynamic mechanical properties of asphalt mixture properly. Since the existing constitutive relation cannot describe well the dynamic viscoelastic properties of asphalt mixture, the fractional derivative viscoelastic model with three elements was adopted and its fitting effect analyzed. The result shown a good fitting for the fractional derivative viscoelastic model with three elements, and a few test parameters were required to build the mode. In addition, these simulating parameters were significant in physics. The order  of the fractional derivative has good correlation with the phase angle, incarnating the viscoelastic proportion of asphalt mixture. So the fractional derivative viscoelastic model with three elements can accurately describe the dynamic mechanical properties of asphalt mixture.

Get full-text (via PubEx)

Ethanol-Mediated Compaction and Crosslinking Enhance Mechanical Properties and Degradation Resistance While Maintaining Cytocompatibility of a Nucleus Pulposus Scaffold

10.1101/333179 ◽

2018 ◽

Author(s):

Joshua D. Walters ◽

Sanjitpal S. Gill ◽

Jeremy J. Mercuri

Keyword(s):

Mechanical Properties ◽

Nucleus Pulposus ◽

Intervertebral Disc Degeneration ◽

Dynamic Mechanical Properties ◽

Matrix Composition ◽

Height Loss ◽

Dynamic Mechanical ◽

Accelerated Degradation ◽

Spine Kinematics ◽

Before And After

AbstractIntervertebral disc degeneration is a complex, cell-mediated process originating in the nucleus pulposus (NP) and is associated with extracellular matrix catabolism leading to disc height loss and impaired spine kinematics. Previously, we developed an acellular bovine NP (ABNP) for NP replacement that emulated human NP matrix composition and supported cell seeding; however, its mechanical properties were lower than those reported for human NP. To address this, we investigated ethanol-mediated compaction and crosslinking to enhance the ABNP’s dynamic mechanical properties and degradation resistance while maintaining its cytocompatibility. First, volumetric and mechanical effects of compaction only were confirmed by evaluating scaffolds after various immersion times in buffered 28% ethanol. It was found that compaction reached equilibrium at ∼30% compaction after 45 min, and dynamic mechanical properties significantly increased 2-6x after 120 min of submersion. This was incorporated into a crosslinking treatment, through which scaffolds were subjected to 120 min pre-compaction in buffered 28% ethanol prior to carbodiimide crosslinking. Their dynamic mechanical properties were evaluated before and after accelerated degradation by ADAMTS-5 or MMP-13. Cytocompatibility was determined by seeding stem cells onto scaffolds and evaluating viability through metabolic activity and fluorescent staining. Compacted and crosslinked scaffolds showed significant increases in DMA properties without detrimentally altering their cytocompatibility, and these mechanical gains were maintained following enzymatic exposure.

Get full-text (via PubEx)

Recycling of waste RFL (Resorcinol-Formaldehyde Latex) Dip Solid in Natural Rubber-based Ply Skim Compound

Progress in Rubber Plastics and Recycling Technology ◽

10.1177/147776060702300303 ◽

2007 ◽

Vol 23 (3) ◽

pp. 181-193

Author(s):

S. Bandyopadhyay ◽

S.L. Agrawal ◽

R. Ameta ◽

S. Dasgupta ◽

R. Mukhopadhyay ◽

...

Keyword(s):

Mechanical Properties ◽

Natural Rubber ◽

Dynamic Mechanical Properties ◽

Waste Material ◽

Resorcinol Formaldehyde ◽

Swell Index ◽

Dynamic Mechanical ◽

Cure Acceleration ◽

Before And After ◽

Tyre Industry

Waste resorcinol – formaldehyde – latex (RFL) dip solid was collected from the suction chamber of a typical tyre industry dip unit. The cure acceleration effect of the waste material was studied in a natural rubber (NR) based filled compound. The effect of the waste material was examined in a natural rubber (NR) based ply skim compound of a bias tyre with cure package modification. Rheological, tack index, stress-strain properties, swell index, dynamic mechanical properties, H-adhesion before and after anaerobic aging was also studied.

Get full-text (via PubEx)