scholarly journals A New Method of Testing the Dynamic Deformation of Metals

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3317
Author(s):  
Jacek Pawlicki ◽  
Zbigniew Stanik ◽  
Adam Płachta ◽  
Andrzej Kubik
Keyword(s):  
Dynamic Deformation ◽  
Construction Materials ◽  
Measuring System ◽  
Materials Testing ◽  
Test Results ◽  
The Finite Element Method ◽  
Short Term ◽  
Bending Tests ◽  
Dynamic Materials ◽  
Energy Consuming

This paper presents the characteristics of a modernized rotary hammer equipped with a new measuring system based on strain gauges for recording short-term signals. The stand makes it possible to carry out dynamic tensile and bending tests in the range of linear speed of the exciting element from 5 to 40 m/s. Initial tests of dynamic deformation and structural studies in the form of fractures carried out on a representative group of metallic materials allowed determining the correlation “strain rate–strain structure”. The proposed new methodology of dynamic materials testing is an original achievement of the authors and may be an effective tool for assessing the properties of construction materials under conditions of dynamic deformation. In practice, the test results can be used to design the structures of energy-consuming elements of vehicles and aircraft load-bearing elements subjected to dynamic loads. Having an extensive database of results from dynamic tests will allow verifying the correctness of calculations of the structure with the use of the finite element method.

scholarly journals Testing Crack Resistance of Non-Load-Bearing Ceramic Walls with Door Openings

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1379
Author(s):  
Tomasz Kania ◽  
Valery Derkach ◽  
Rafał Nowak
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Building Structure ◽  
The Finite Element Method ◽  
Short Term ◽  
Load Bearing ◽  
Door Opening ◽  
Partition Walls ◽  
Internal Partition ◽  
New Buildings

Cracking in non-load-bearing internal partition walls is a serious problem that frequently occurs in new buildings within the short term after putting them into service or even before completion of construction. Sometimes, it is so considerable that it cannot be accepted by the occupiers. The article presents tests of cracking in ceramic walls with a door opening connected in a rigid and flexible way along vertical edges. The first analyzes were conducted using the finite element method (FEM), and afterward, the measurements of deformations and stresses in walls on deflecting floors were performed on a full scale in the actual building structure. The measurements enabled to determine floor deformations leading to cracking of walls and to establish a dependency between the values of tensile stresses within the area of the door opening corners and their location along the length of walls and type of vertical connection with the structure.

Effect of Hydrogen on Mechanical Properties of Pipeline API 5L X70 Steel

2011 ◽  
Vol 146 ◽  
pp. 213-225 ◽  
Author(s):  
T. Bellahcene ◽  
J. Capelle ◽  
Méziane Aberkane ◽  
Z. Azari
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Embrittlement ◽  
Hydrogen Absorption ◽  
Fatigue Tests ◽  
The Finite Element Method ◽  
Effective Distance ◽  
Bending Tests ◽  
Fatigue Initiation ◽  
Api 5L X70 Steel ◽  
Special Soil

The aim of this work is to study the effects of hydrogen absorption on mechanical properties of pipe API 5L X70 steel. This study is conducted in special soil solution NS4 with pH 6.7 It show that the tensile properties like yield stress, ultimate strength and elongation at failure reduced under hydrogen embrittlement. Several fatigue tests (three (03) points bending tests) on roman tile specimens with notch are performed. Fatigue initiation is detected by acoustic emission. A comparison between specimens electrolytically charged with hydrogen and specimens without hydrogen absorption is made and it has been noted that fatigue initiation time is reduced when hydrogen embrittlement occurs. The field of elastoplastic stresses near the notch is computed by the finite-element method with the Abaqus software package. Effective distance and stress are calculated with the volumetric approach and the Notch intensity Factor of the roman tile specimen is determined for each loading value used in our tests.

Measurement and Analysis on Transient Thermal Characteristics of High Speed Motorized Spindle

2011 ◽  
Vol 52-54 ◽  
pp. 2021-2026
Author(s):  
Gui Ling Deng ◽  
Can Zhou
Keyword(s):  
High Speed ◽  
Thermal Deformation ◽  
Thermal Characteristics ◽  
Measuring System ◽  
Test Results ◽  
Motorized Spindle ◽  
Measurement And Analysis ◽  
Turning Center ◽  
Transient Thermal ◽  
Deformation Compensation

Thermal deformation is an important factor to affect the accuracy of the motorized spindle, the core component of high-speed machine tool. To understand the spindle system transient thermal characteristics of the high-speed turning center CH7516GS, some high-precision sensors and high-frequency data acquisition system is used to establish the temperature and displacement measuring system. The thermal deformation compensation model is established on the basis of the experimental test results.

Modified Equation to Predict Leak/Rupture Criteria for Axially Through-Wall Notched X80 and X100 Linepipes Having Higher Charpy Energy

2004 ◽  
Author(s):  
Shinobu Kawaguchi ◽  
Naoto Hagiwara ◽  
Mitsuru Ohata ◽  
Masao Toyoda
Keyword(s):  
Fracture Toughness ◽  
Flow Stress ◽  
Pipe Material ◽  
Test Results ◽  
Absorbed Energy ◽  
Bending Tests ◽  
Full Scale Tests ◽  
Hoop Stresses ◽  
The Relationship ◽  
Modified Equation

A method of predicting the leak/rupture criteria for API 5L X80 and X100 linepipes was evaluated, based on the results of hydrostatic full-scale tests for X60, X65, X80 and X100 linepipes with an axially through-wall (TW) notch. The TW notch test results clarified the leak/rupture criteria, that is, the relationship between the initial notch lengths and the maximum hoop stresses during the TW notch tests. The obtained leak/rupture criteria were then compared to the prediction of the Charpy V-notch (CVN) absorbed energy-based equation, which has been proposed by Kiefner et al. The comparison revealed that the CVN-based equation was not applicable to the pipes having a CVN energy (Cv) greater than 130 J and flow stress greater than X65. In order to predict the leak/rupture criteria for these linepipes, the static absorbed energy for ductile cracking, (Cvs)i, was introduced as representing the fracture toughness of a pipe material. The (Cvs)i value was determined from the microscopic observation of the cut and buffed Charpy V-notch specimens after static 3-point bending tests. The CVN energy in the original CVN-based equation was replaced by an equivalent CVN energy, (Cv)eq’ which was defined as follows: (Cv)eq = 4.5 (Cvs)i. The leak/rupture criteria for the X80 and X100 linepipes with higher CVN energies were reasonably predicted by the modified equation using the (Cvs)i value.

Experimental Study on the Interaction Effect of Sulfate Ions and Chloride Ions on Reinforcement Corrosion in Marine Environment

2017 ◽  
Author(s):  
Yi Huang ◽  
Yunze Xu ◽  
Xiaona Wang ◽  
Shide Song ◽  
Lujia Yang
Keyword(s):  
Passive Film ◽  
Pore Solution ◽  
Construction Materials ◽  
Chloride Ions ◽  
Localized Corrosion ◽  
Test Results ◽  
Reinforcement Corrosion ◽  
Marine Structures ◽  
Sulfate Ions ◽  
Corrosion Risk

Reinforced concrete is one of the most widely used construction materials for marine structures. Due to the abundance of the aggressive ions such as chloride ions and sulfate ions in the seawater, the reinforcement exposed to the marine and costal environment are exposed to a high corrosion risk. Localized corrosion will occur once the passive film on the rebar is damaged. In this work, the corrosion behavior of the steel in the simulated pore solution containing with both sulfate ions and chloride ions are studied by using cyclic potentialdynamic polarization methods and the corrosion morphologies observed using scanning electron microscope (SEM). The test results show that the initial rebar corrosion is caused by the absorption of the chloride ions in the passive film. The sulfate ions nearly had no effect on the corrosion of the rebar in pore solution and it can further mitigate the pitting corrosion in chloride containing pore solution.

scholarly journals Effects of extended short-term aging duration on asphalt binder behaviour at high temperatures

2016 ◽  
Vol 11 (4) ◽  
pp. 302-312 ◽  
Author(s):  
Meor Othman Hamzah ◽  
Seyed Reza Omranian
Keyword(s):  
Response Surface ◽  
Response Surface Method ◽  
High Temperatures ◽  
Test Temperature ◽  
Asphalt Binder ◽  
Pavement Performance ◽  
Test Results ◽  
Aging Effects ◽  
Short Term ◽  
Surface Method

Many factors affecting pavement performance include variations in binder composition and environmental conditions during asphalt mixture production. Hence, predicting pavement performance is a difficult task. This paper aims to investigate the effects of short term aging on binder viscosity at high temperature. In order to predict the effects of short term aging on the asphalt binder viscosity at high temperatures, a Response Surface Method was performed on the Rotational Viscometer test results. An experimental matrix was planned based on the central composite design for aging duration and test temperature. The test results showed that aging increased the binder viscosity, while increasing test temperature decreased the corresponding value. However, aging effects differ and depend on binder types, test temperatures and aging conditions. It was also found that the Response Surface Method is a fast, effective and reliable method to predict the effects of aging on binder viscosity behaviour at high temperatures.

The Fatigue Performance of High Performance Concrete Composite Girder

2019 ◽  
Author(s):  
C. Xu ◽  
B. Y. Zhang ◽  
Z. H. Hou
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Test Results ◽  
Normal Concrete ◽  
Bending Tests ◽  
Composite Girder ◽  
Tensile Performance ◽  
Negative Bending ◽  
The One ◽  
Push Out

<p>The application of high performance concrete has been increasingly concerned in the negative flexural region of steel‐concrete continuous composite girder because of its favorable tensile performance. However, the unclear cyclic and ultimate performance of a high performance concrete composite girder results to the problems which hinder the further application. In this case, a series of fatigue negative bending tests on HPC composite girders and fatigue push‐out tests on stud connectors in HPC were executed. The test results showed that the fatigue slip in the HPC composite girder was smaller than the normal concrete composite girder, and the fatigue life of stud in HPC was longer than the one in normal concrete. Meanwhile, according to the comparison between the stud fatigue live evaluations and test results, the AASHTO‐based evaluations were comparatively with larger safety redundancy, and JSCE was close to the test results but had smaller safety redundancy.</p>

Sign in / Sign up

Export Citation Format

Share Document