scholarly journals Design and Demonstration of a Low-Cost Small-Scale Fatigue Testing Machine for Multi-Purpose Testing of Materials, Sensors and Structures

Machines ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 30 ◽  
Author(s):  
Jack McAlorum ◽  
Tim Rubert ◽  
Grzegorz Fusiek ◽  
Pawel Niewczas ◽  
Giorgio Zorzi

Mechanical fatigue testing of materials, prototype structures or sensors is often required prior to the deployment of these components in industrial applications. Such fatigue tests often requires the continuous long-term use of an appropriate loading machine, which can incur significant costs when outsourcing and can limit customization options. In this work, design and implementation of a low-cost small-scale machine capable of customizable fatigue experimentation on structural beams is presented. The design is thoroughly modeled using FEM software and compared to a sample experiment, demonstrating long-term endurance of the machine. This approach to fatigue testing is then evaluated against the typical cost of outsourcing in the UK, providing evidence that, for long-term testing of at least 373 h, a custom machine is the preferred option.

Author(s):  
Naoki Osawa ◽  
Tetsuya Nakamura ◽  
Norio Yamamoto ◽  
Junji Sawamura

A new simple fatigue testing machine, which can carry out fast and low-cost fatigue tests of welded joints subject to wave with high frequency vibration, has been developed. This machine is designed for plate bending type fatigue tests, and wave load is applied by using motors with eccentric mass. Springing vibration is superimposed by attaching an additional vibrator to the test specimen, and whipping vibration is superimposed by an intermittent hammering. Fatigue tests which simulate springing and whipping by a conventional servo-type fatigue testing machines are very expensive and use a large amount of electricity. If one uses these conventional machines, it is difficult to simulate superimposed stress wave forms at high speed, and it takes long hours of testing to examine the high frequency effect. In contrast, it is found that fatigue tests can be carried out in fast, i.e. waves with 10Hz or higher frequency for out-of-plane gusset welded joint specimens with 12mm plate thickness by using the developed machine. The electricity to be used for fatigue tests could be minimal, for example one thousandth of that needed for conventional machines. These results demonstrate the superiority of the developed machine.


2016 ◽  
Vol 17 ◽  
pp. 14-30 ◽  
Author(s):  
Okechukwu P. Nwachukwu ◽  
Alexander V. Gridasov ◽  
Ekaterina A. Gridasova

This review looks into the state of gigacycle fatigue behavior of some structural materials used in engineering works. Particular attention is given to the use of ultrasonic fatigue testing machine (USF-2000) due to its important role in conducting gigacycle fatigue tests. Gigacycle fatigue behavior of most materials used for very long life engineering applications is reviewed.Gigacycle fatigue behavior of magnesium alloys, aluminum alloys, titanium alloys, spheroid graphite cast iron, steels and nickel alloys are reviewed together with the examination of the most common material defects that initiate gigacycle fatigue failures in these materials. In addition, the stage-by-stage fatigue crack developments in the gigacycle regime are reviewed. This review is concluded by suggesting the directions for future works in gigacycle fatigue.


2021 ◽  
Vol 2115 (1) ◽  
pp. 012026
Author(s):  
Sonam Solanki ◽  
Gunendra Mahore

Abstract In the current process of producing vermicompost on a large-scale, the main challenge is to keep the worms alive. This is achieved by maintaining temperature and moisture in their living medium. It is a difficult task to maintain these parameters throughout the process. Currently, this is achieved by building infrastructure but this method requires a large initial investment and long-run maintenance. Also, these methods are limited to small-scale production. For large-scale production, a unit is developed which utilises natural airflow with water and automation. The main aim of this unit is to provide favourable conditions to worms in large-scale production with very low investment and minimum maintenance in long term. The key innovation of this research is that the technology used in the unit should be practical and easy to adopt by small farmers. For long-term maintenance of the technology lesser number of parts are used.


2012 ◽  
Vol 2012 (CICMT) ◽  
pp. 000371-000376 ◽  
Author(s):  
Marina Santo Zarnik ◽  
Darko Belavic

This paper discusses the stability of a piezoresistive, LTCC-based, pressure sensor that was designed for measurements in a low-pressure range below 100 mbar. The intrinsic stability of the sensor's offset was evaluated at a constant ambient temperature and different conditions regarding the atmospheric humidity. The sensors were also subjected to functional fatigue tests, which included a full-scale and an overload pressure cycling. The results of the fatigue testing revealed the vulnerability of the sensor's structure from the point of view of the long-term stability and the life-cycle. Nevertheless, the stability of the key characteristics of the prototype sensors was found to be satisfactory for accurate measurements in the low-pressure ranges.


2017 ◽  
Vol 734 ◽  
pp. 194-201 ◽  
Author(s):  
Yutaka Konishi ◽  
Takamoto Itoh ◽  
Masao Sakane ◽  
Fumio Ogawa ◽  
Hideyuki Kanayama

This paper investigates the fatigue results in low cycle fatigue region obtained from a miniaturized specimen having a 6mm gage length, 3mm diameter and 55mm total length. Fatigue tests were performed for two type lead-free solders using horizontal-type electrical servo hydraulic push-pull fatigue testing machine. Materials employed were Sn-3.0Ag-0.5Cu and Sn-5Sb. The results from Sn-3.0Ag-0.5Cu were compared with those obtained using a bulk specimen in a previous study. Relationship between strain range and number of cycles to failure of the small-sized specimen agreed with those of the bulk specimens. The testing techniques are applicable to Sn-5Sb following the Manson-Coffin law. These results confirm that the testing technique proposed here, using small-sized specimen, is suitable to get fruitful fatigue data for lead-free solder compounds.


Author(s):  
C. Bharatiraj ◽  
JL Munda ◽  
Ishan Vaghasia ◽  
Rajesh Valiveti ◽  
P. Manasa

The DC motors an outstanding portion of apparatus in automotive and automation industrial applications requiring variable speed and load characteristics due to its ease of controllability. Creating an interface control system for multi DC motor drive operations with centralized speed control, from small-scale models to large industrial applications much demand. By using Lab VIEW (laboratory virtual instrument engineering workbench) as the motor controller, can control a DC motor for multiple purposes using single software environment. The aim of this paper is to propose the centralized speed control of DC motor using Lab VIEW. Here, the Lab VIEW is used for simulating the motor, whereas the input armature voltage of the DC motor is controlled using a virtual Knob in Lab VIEW software. The hardware part of the system (DC motor) and the software (in personal computer) are interfaced using a data acquisition card (DAQ) -Model PCI- 6024E. The voltage and Speed response is obtained using LABVIEW software. Using this software, group of motors’ speed can be controlled from different location using remote telemetry. The propose work also focuses on controlling the speed of the individual DC motor using PWM scheme (Duty cycle based Square wave generation) and DAQ. Help of the DAQ along with Lab VIEW front panel window, the DC motor speed and directions can be change easily in remote way. In order to test the proposed system the laboratory model for an 80W DC motor group (multi drive) is developed for different angular displacements and directions of the motor. The simulation model and experimental results conforms the advantages and robustness of the proposed centralized speed control.


2018 ◽  
Vol 32 (19) ◽  
pp. 1840055 ◽  
Author(s):  
Jong Seok Kim ◽  
Yeong Min Park ◽  
Sang Yoon Kim ◽  
Mun Ki Bae ◽  
Dong Qi ◽  
...  

Fretting occurs at the contact area between two materials under load and in the presence of minute relative surface motion by vibration or external force. Bearings, clutches, riveted and bolted lap joints are subjected to fretting damage. Friction coefficient, materials of the specimen, contact surface pressure, relative slip amplitudes, temperatures and environment have an effect on the fretting. In this study, fretting wear test is conducted with SCM415 (Cr–Mo alloy steel) which are much used for making gears and shafts because of its excellent machinability, good mechanical properties and low cost, compared with those of the existing machine structural steels. In order to determine the fretting wear type, fretting wear fixture which can be attached to the servo hydraulic fatigue testing machine is made. And then, specimens and fretting pad with a constant curvature are made of SCM415 materials. Different normal forces and displacement amplitudes are applied to the fretting pad and diamond-like carbon (DLC) is coated on the fretting pad for fretting wear test.


2007 ◽  
Vol 353-358 ◽  
pp. 142-145 ◽  
Author(s):  
Ki Weon Kang ◽  
Byeong Choon Goo ◽  
J.H. Kim ◽  
Heung Seob Kim ◽  
Jung Kyu Kim

This paper deals with the fatigue behavior and its statistical properties of SM490A steel at various temperatures, which is utilized in the railway vehicle. For these goals, the tensile ad fatigue tests were performed by using a servo-hydraulic fatigue testing machine at three temperatures: +20°C, -10°C and -40°C. The static strength and fatigue limits of SM490A steel were increased with decreasing of test temperature. The probabilistic properties of fatigue behavior are investigated by means of probabilistic stress-life (P-S-N) curve and they are well in conformance with the experimental results regardless of temperature. Also, based on P-S-N curves, the variation of fatigue life is investigated and as the temperature decreases, the variation of fatigue life increases moderately.


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