Experimental Investigations of Capacity Response of Root Piles on Combination of O-Cell Test and Conventional Head-Down Test Methods

Currently, the railroad industry is leaning towards alternative solutions to hardwood timber for crossties applications. This trend is part of an effort to increase train speeds beyond the wooden crossties capacity and minimize the negative environmental effects associated with them. Among the available alternatives are recycled plastic composite crossties. Their sustainably, environmental benefits, durability performance and ease of installation or one to one replacement of timber crossties render them an attractive and competitive solution. Several research programs have studied this material in the past. However, additional research is required to fully understand the behavior of these materials. This study aims to investigate the performance of fastening system used for recycled High Density Polyethylene crossties. The study encompasses comprehensive experimental investigations and analytical finite element modeling. The testing program evaluated each of the fastening system components using static test methods recommended by the AREMA manual. These tests addressed the spike pullout and lateral restraint for both screw and cut spikes as well as the fastening system uplift behavior. Moreover cyclic testing was also conducted on the full system to study the interactions of the fastening system components with the plastic composite crosstie. Finite element models were constructed and calibrated using the experimental data in order to extrapolate on the experimental results and predict different scenarios. The results observed in this study showed great promise highlighting the potential of these material if properly optimized and engineered.

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Test Methods for Measuring Mechanical Parameter of Simulated Lunar Dust

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.333-335.389 ◽

2013 ◽

Vol 333-335 ◽

pp. 389-393

Author(s):

Man Li ◽

Dong Bo Tian ◽

Zhi Hao Wang ◽

Yu Bai ◽

Hui Qi Zheng ◽

...

Keyword(s):

Mechanical Property ◽

Void Ratio ◽

Friction Angle ◽

Test Methods ◽

Experimental Investigations ◽

The Moon ◽

Engineering Property ◽

Lunar Dust ◽

Large Numbers ◽

Moon Exploration

Due to the preciousness of real lunar dust, the lunar dust simulant is usually employed to replace the real one in the large numbers of experimental investigations about its mechanical property and engineering property. Therefore, the investigation on mechanical property of lunar dust simulant is also extremely significant. This research has put forward several methods for measuring mechanical property, which are used to measure the parameters including particle size distribution, particle proportion, relative density, void ratio, cohesion, internal friction angle, etc. of lunar dust simulant. The lunar dust simulant is determined to be suitable for application in the moon exploration project experiment after comparing these parameters with relevant typical mechanical parameters of foreign lunar dust simulant.

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Experimental Study of Hardened Young’s Modulus for 3D Printed Mortar

Materials ◽

10.3390/ma14247643 ◽

2021 ◽

Vol 14 (24) ◽

pp. 7643

Author(s):

Szymon Skibicki ◽

Mateusz Techman ◽

Karol Federowicz ◽

Norbert Olczyk ◽

Marcin Hoffmann

Keyword(s):

Young’S Modulus ◽

Young's Modulus ◽

Statistical Correlation ◽

Test Methods ◽

Cylindrical Sample ◽

Experimental Investigations ◽

Current Standard ◽

Number Of Layers ◽

3D Printed

Few studies have focused on determining the Young’s modulus of 3D printed structures. This study presents the results of experimental investigations of Young’s modulus of a 3D printed mortar. Specimens were prepared in four different ways to investigate possible application of different methods for 3D printed structures. Study determines the influence of the number of layers on mechanical properties of printed samples. Results have shown a strong statistical correlation between the number of layers and value of Young’s modulus. The compressive strength and Young’s modulus reduction compared to standard cylindrical sample were up to 43.1% and 19.8%, respectively. Results of the study shed light on the differences between the current standard specimen used for determination of Young’s modulus and the specimen prepared by 3D printing. The community should discuss the problem of standardization of test methods in view of visible differences between different types of specimens.

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Experimental investigations on the failures of woven textile sandwich panels

Journal of Thermoplastic Composite Materials ◽

10.1177/0892705715598357 ◽

2016 ◽

Vol 30 (2) ◽

pp. 196-224 ◽

Cited By ~ 3

Author(s):

Yang Hu ◽

Wanxin Li ◽

Hualin Fan ◽

Fangfang Sun ◽

Jianfeng Ouyang ◽

...

Keyword(s):

Failure Modes ◽

Shear Failure ◽

Structural Characteristics ◽

Test Methods ◽

National Standards ◽

Experimental Investigations ◽

Uniaxial Stretching ◽

Three Point Bending ◽

Woven Textile ◽

Bending Fracture

To reveal the deformation, strength, and failure modes of woven textile sandwich composites (WTSCs), test methods suggested by national standards were referenced and discussed to carry out flatwise and edgewise compression experiments, uniaxial stretching experiments, and three-point bending experiments according to the structural characteristics of WTSC. Strength and failure modes of WTSCs in flatwise compression and uniaxial tension were acquired. Anisotropy and size dependency of strength and failure modes of WTSC panels in edgewise compression were revealed. Strength of weft-compressed panels has few variations when the length is smaller than 60 mm and then decreases obviously when the length is over 60 mm, accompanying with the failure modes turning from crushing, fracture to buckling. Progressive crushing and bending fracture are two observed post-failure modes. Two competing shear failure modes and facesheet failure were observed in three-point bending experiments. Shear strength of the woven core of WTSC was deduced by beam flexure. To acquire facesheet failure mode by long beam flexure, the span should be above 36 times the thickness of the panel.

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Development of a Sulfate Resistance Performance Test for Concrete by Tensile Strength Measurements: Determination of Test Conditions

Crystals ◽

10.3390/cryst11081001 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1001

Author(s):

Johannes Haufe ◽

Anya Vollpracht ◽

Thomas Matschei

Keyword(s):

Tensile Strength ◽

Performance Test ◽

Storage Temperature ◽

Direct Method ◽

Sulfate Solution ◽

Test Methods ◽

Experimental Investigations ◽

Sulfate Resistance ◽

Binder Type ◽

Physical Resistance

Assessing the sulfate resistance of concrete is essential for the use of concrete in sulfate rich environments. A multitude of test methods exists worldwide, showing the relevance of the problem and the difficulty to find a suitable test setup. Testing the relative tensile strength of ASTM C307 concrete briquette specimens after exposure to a sulfate solution is a new direct method to assess the degree of deterioration. The aim of this study is to develop a new performance test, which considers both the chemical and physical resistance of a specific concrete mix against sulfate attack. In the experimental investigations, the binder type, storage temperature, type and concentration of sulfate solution, and concrete composition were varied, and the remaining tensile strength evaluated to define the test parameters. To gain significantly distinguishable data within nine months of storage, the use of sodium sulfate solution with 6000 mg SO42−/l at 5 °C is proposed.

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