scholarly journals On a throw-testing machine for reversals of mean stress

1902 ◽  
Vol 70 (459-466) ◽  
pp. 44-46
Keyword(s):  
Periodic Motion ◽  
Testing Machine ◽  
Vertical Direction ◽  
Inertia Force ◽  
Mean Stress ◽  
Connecting Rod ◽  
Direct Tension ◽  
Repeated Stress ◽  
Tension And Compression

The present research, which was carried on in the Whitworth Engineering Laboratory of the Owens College, Manchester, was undertaken at the suggestion of Professor Osborne Reynolds, who proposed an investigation of “repeated stress” on the following lines:—The stress should be direct tension, and compression of approximately equal amounts, such tension and compression being obtained by means of the inertia force of an oscillatory weight. The rapidity of repetitions should be much higher than in the experiments of Wöhler, Spangenberg, Bauschinger, and Baker—in fact, ranging as high as 2000 reversals per minute. In the apparatus employed a weight is supported vertically by means of the specimen to be tested, and the upper part of the specimen receives a periodic motion in a vertical direction by means of a crank and a connecting rod.

scholarly journals IV. On a throw-testing machine for reversals of mean stress

1902 ◽  
Vol 199 (312-320) ◽  
pp. 265-297 ◽  
Keyword(s):  
Maximum Stress ◽  
Testing Machine ◽  
Breaking Stress ◽  
Mean Stress ◽  
Iron And Steel ◽  
Wrought Iron ◽  
Repeated Stress ◽  
Series Of Experiments

In 1860, Sir W. Fairbairn, using a riveted girder, carried out a series of experiments, which seem to be the first recorded experiments on Repeated Stress. From 1860 to 1870, Wöhler carried out his laborious and valuable researches on the Fatigue of Wrought Iron and Steel. From his results published in the ‘Zeitschrift fur Bauwesen,’ Berlin, the following important points may be deduced:— (1) That these materials (wrought iron and steel) will rupture with stresses much below the statical breaking stress, if such stress be repeated a sufficient number of times. (2) That within certain limits, the range of stress, and not the maximum stress, determines the number of reversals necessary for rupture. (3) That as the range of stress is diminished, the number of repetitions for rupture increases. (4) That there is a limiting range of stress for which the number of repetitions of stress for rupture becomes infinite. (5) That this limiting range of stress diminishes as the maximum stress increases.

Tensile and Compressive Properties of Poly(P-Phenylene Benzobisoxazole) Fiber

1988 ◽  
Vol 134 ◽  
Author(s):  
S. A. Fawaz ◽  
A. N. Palazotto ◽  
C. S. Wang
Keyword(s):  
Testing Machine ◽  
Tensile Modulus ◽  
Gauge Length ◽  
Single Fiber ◽  
Direct Tension ◽  
Tensile Testing Machine ◽  
Axial Tensile ◽  
Tension And Compression ◽  
Small Gauge ◽  
Fiber Misalignment

Axial tensile modulus, compressive modulus and compressive strength of poly(p-phenylene benzobisoxazole) fiber were measured with a Tecam Micro-tensile Testing Machine. This machine was configured to allow direct tension and compression testing of a single fiber at extremely small gauge length. The measured tensile and compressive moduli were analyzed for machine compliance corrections and possible gauge length error. Results were discussed for the effects of non-uniform stress distribution and fiber misalignment. By comparing the axial compressive strengths measured from various single fiber characterization techniques, direct compression furnished data closer to that measured from composite compressive tests.

Mechanical Properties Comparison of Different La Content in AZ91

2014 ◽  
Vol 620 ◽  
pp. 67-72 ◽  
Author(s):  
Yan Yan Zhang ◽  
Chun Xia He ◽  
Hang Song Yang ◽  
Jian Xiu Liu
Keyword(s):  
Magnesium Alloy ◽  
Mechanical Performance ◽  
Testing Machine ◽  
Powder Metallurgy Method ◽  
Az91 Magnesium Alloy ◽  
Compression Performance ◽  
Hardness Tester ◽  
Mechanics Performance ◽  
Tension And Compression ◽  
Az91 Magnesium

In order to improve the comprehensive mechanics performance of AZ91 magnesium alloy which is used as car's material, the La element was added in AZ91 magnesium alloy and specimens was prepared by powder metallurgy method. The influence of La on microstructure, hardness and compression performance of AZ91 a magnesium alloy specimen was studied using metallographic electronic microscope, hardness tester, universal tension and compression testing machine. The experimental results show that when amount of La's addition is 1.2%, its mechanical performance is best, hardness is 67.1 HV, compressive strength is 115.8 MPa, increased respectively by 20.0% and 29.5% compared the AZ91 magnesium alloy substrate, and the grain refinement effect of AZ91 magnesium alloy is the best at this time.

scholarly journals Development of a Micro/Nano Probing System Using Double Elastic Mechanisms

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4229 ◽  
Author(s):  
Rui-Jun Li ◽  
Peng Xu ◽  
Peng-Yu Wang ◽  
Kuang-Chao Fan ◽  
Rong-Jun Cheng ◽  
...  
Keyword(s):  
Mathematical Models ◽  
Precision Measurement ◽  
Vertical Direction ◽  
3D Measurement ◽  
Connecting Rod ◽  
High Precision Measurement ◽  
Coordinate Measurement ◽  
Coordinate Measurement Machine ◽  
System A ◽  
Elastic Mechanism

To meet the requirement of high precision measurement of coordinate measurement machine system, a compact microprobe has been designed for 3D measurement in this paper. Aiming to reduce the influences of signal coupling during the probing process, the probe has been designed by adopting two elastic mechanisms, in which the horizontal and vertical motions of the probe tip can be separated by differential signals of quadrant photodetectors in each elastic mechanism. A connecting rod has been designed to transfer the displacement of the probe tip in vertical direction from lower to upper elastic mechanisms. The sensitivity models in horizontal and vertical directions have been established, and the sensor sensitivity has been verified through experiments. Furthermore, the signal coupling of three axes has been analyzed, and mathematical models have been proposed for decoupling. The probing performance has been verified experimentally.

The Finite Element Analysis of Tension and Compression Condition of Diesel Engine Connecting Rod

2014 ◽  
Vol 722 ◽  
pp. 120-124 ◽  
Author(s):  
Gang Chen ◽  
Lei Wu ◽  
Long Wu ◽  
Pei Qing Xie
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Diesel Engine ◽  
Reference Value ◽  
Production Cycle ◽  
Connecting Rod ◽  
Analysis Software ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Tension And Compression

In this paper, through the finite element analysis software ANSYS, analysis and research on the part drawing of the diesel engine connecting rod. Using pro/e modeling, introduce it into the finite element analysis software ANSYS for the finite element static analysis of the state of load on the connecting rod. Setting correct model, partitioning appropriate mesh, and setting a reasonable process solution, it can generate visual stress nephogram to facilitate access to important data and intuitive understanding. There is a certain reference value to guide the practical production and shorten the production cycle of the product.

Research on Material Fatigue Test of Steel Fiber Reinforced Concrete under Tension and Compression Loading

2017 ◽  
Vol 730 ◽  
pp. 353-357
Author(s):  
Meng Meng Guo ◽  
Zhong Ren Feng ◽  
Yang Chen
Keyword(s):  
Reinforced Concrete ◽  
Fatigue Strength ◽  
Steel Fiber ◽  
Testing Machine ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Compression Loading ◽  
Ordinary Concrete ◽  
Tension And Compression

Using the material testing machine of electro-hydraulic servo fatigue tests had been carried out on ordinary concrete and steel fiber reinforced concrete. The fatigue life, strength, stress and strain had been measured under tension and compression loading. The variation of fatigue was analyzed based on the test results. Having regression analysis, obtained the fatigue strength. Mean-while, the fatigue strain-life curves of ordinary concrete and steel fiber reinforced concrete had been made after data processing. The results had been showed that the fatigue property of steel fiber reinforced concrete was significantly higher than that of ordinary concrete. And the fatigue strength increased about 32.6% compared with ordinary concrete. The tensile and compressive fatigue strain were slightly smaller than that of ordinary concrete.

Control System Design and Precision Analysis of the Spring Testing Machine

2014 ◽  
Vol 701-702 ◽  
pp. 573-576
Author(s):  
Han Zhang ◽  
Liang Zhi Zhang ◽  
Yan Mei Lei
Keyword(s):  
Control System ◽  
System Design ◽  
Measurement Accuracy ◽  
Testing Machine ◽  
Touch Screen ◽  
Control System Design ◽  
Distortion Compensation ◽  
Measurement Results ◽  
Tension And Compression ◽  
Sd Card

The control system of the spring tension and compression testing machine is designed based on STM32 processor and touch screen. The signal of the pull-pressure sensor after conditioning is conversed by the 24bit A/D converter. The signal is operated real-timely with the encoder data, the setting value of the touch screen and the condition of the keys. The results are stored in the SD card. While the results are displayed on the touch screen. The anti-interference capability of the system is improved by the hardware and software anti-interference design. The reason of the measurement results smaller than the theoretical value is analyzed according to the tests results used of the calibration texting machines. Two aspects of the measures have been proposed to improve the measurement accuracy, including improving hardware stiffness and introducing distortion compensation amount.

Effect of Pre-Crack on Fatigue Behaviors of Concrete under Tension and Compression Loading

2016 ◽  
Vol 873 ◽  
pp. 110-114
Author(s):  
Meng Meng Guo ◽  
Zhong Ren Feng ◽  
Xiong Jiang Wang
Keyword(s):  
Fatigue Life ◽  
Fatigue Behavior ◽  
Testing Machine ◽  
Great Influence ◽  
Compression Loading ◽  
Software Analysis ◽  
Finite Element Software ◽  
Tension And Compression ◽  
Hydraulic Servo ◽  
Material Testing Machine

With the material testing machine of electro-hydraulic servo, fatigue test have been carried out on coarse aggregate concrete with pre-crack .The fatigue life and fatigue strength of the concrete have been measured under tension and compression loading. The effect of pre-crack on concrete fatigue behavior has been analyzed based on the test results. Having regression treatment, obtained the concrete S-N curve and S-lgN curve of fatigue life. Mean-while, applying ANSYS finite element software, analysis and comparison of the fatigue behavior have been performed. The results show that pre-crack has a great influence on the fatigue behavior of concrete, and the fatigue life is reduced for 75%~80%.

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