Fatigue testing device

Anti-buckling assembly prevents buckling of sheet metal fatigue specimen when axial compressive load is applied. It provides for cyclic heating and cooling of specimen during testing. Assembly permits tests at two locations on specimen. Device has ports for visual, optical, or photographic monitoring of fatigue crack propagation in test specimen

Material Fatigue Testing System

A system for cyclicly applying a varying load to a material under test is described. It includes a load sensor which senses the magnitude of load being applied to a material, and, upon sensing a selected magnitude of loading, causes the load to be maintained for a predetermined time and then cause the system to resume cyclical loading

A fabrication history based strain-fatigue model for prediction of crack initiation in a radial loading wheel

A strain-based fatigue model concerning fabrication history is applied to predict the fatigue life of a commercial car wheel under radial loads. As the prior conditions, the strain fatigue testing is performed on standard specimen of DP590 and FB540 steels at various fabrication states, including raw materials, pre-strain and pre-strain + bake. Furthermore, the strain distribution of car wheel during its rotation under radial loads is simulated via ANSYS. The fatigue properties mainly determined by crack initiation of car wheels at various fabrication states are predicted via local stress–strain method, in which the scale and surface factors are also taken into account. The radial fatigue testing is carried out, and the results are used to validate the present model. The fracture mechanism is analysed using FEI Nova 400 field emission gun scanning electron microscope

Multiaxial fatigue low cycle fatigue testing

Multiaxial testing methods are reviewed. Advantages and disadvantages of each type test is discussed. Significant multiaxial data available in the literature is analyzed. The yield theories are compared for multiaxial fatigue analysis

Testing methodologies for corrosion fatigue

Offshore constructions are subjected to cyclic loading conditions. This situation is combined with the corrosive nature of the surrounding environment. It is of actual concern whether the combined effect is more damaging or not than the superposition of each effect independently. This literature review first introduces the reader to corrosion fatigue. Thereafter a critical comparison of some typical lab-scale fatigue corrosion test setups is given. Special emphasis is devoted to the instrumentation of the setup. This is followed by a design criteria summary which will be used to design a new corrosion fatigue test set-up for evaluating the fatigue properties of steel components in sea water environment

Test report on fatigue-testing of nickel-200 panels

Nickel-200 fatigue testing for thermal fatigue data on regeneratively cooled hypersonic research engine structure

Horizontal cryostat for fatigue testing Patent

Cryostat for use with horizontal fatigue testing machines at low temperature

Estimating the fatigue law of asphalt mixtures using a strain sweep test (EBADE test)

Fatigue characterization of asphalt mixtures is a very important issue. However, existing techniques to that end are expensive and time consuming. For that reason the asphalt technicians have been studying several different methods to reduce the testing time needed. Such is the case of the Visco-Elastic Continuum Damage models. In that regard, this paper presents the efforts carried out by the Road Research Laboratory at the UPC-BarcelonaTech to reduce that testing time, by implementing a strain sweep test and approximating the fatigue law of the material from the data obtained. The EBADE test was applied to four mixtures for which the conventional fatigue laws were obtained using time sweep tests. The data collected was used to fit a fatigue model based on two strain values that can be directly computed from the EBADE test, namely Failure strain and No Damage strain. A good correlation was found between the model proposed and the experimental data.Postprint (published version

Fatigue test bench manufacturing by reusing a parallel lathe

Fatigue life of machined parts strongly depends on their surface condition. The rotating bar bending fatigue testing method is widely used to obtain the fatigue behavior of metallic materials due to its simplicity. In this work, the methodology for the design, manufacturing and setup of a fatigue test bench is exposed. The main novelty lies on the reuse of several elements from an old parallel lathe, currently out of order, and their use to manufacture some parts for the test bench. In this way, a double objective is achieved: high quality elements are recycled and the machine manufacturing cost is reduced.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Fatigue life prediction of z-fibre pinned composite laminate under mode I loading

A hybrid method is presented combining linear elastic fracture mechanics with nonlinear damage mechanics that can predict the fatigue crack growth rate in z-fibre pinned composites under mode I loading. The strain energy release rate is evaluated using the virtual crack closure technique via finite element analysis. Cohesive elements are used in the pinned region to represent the crack bridging force generated by the pins. The reduction of the pins' bridging force under the fatigue loading is accommodated by applying a degradation law, based on damage mechanics with empirical fitting parameters. A modified degradation law is proposed which is capable of accumulating fatigue damage under varying crack opening displacement ranges experienced by the pins during fatigue loading. Fatigue testing was performed with a z-pinned double cantilever beam at two different values of applied displacement amplitude. The predictions show reasonably good agreement with the test results in terms of the fatigue crack propagation rate and fatigue life