Double axis fatigue life prediction based on finite element analysis for aluminum alloy wheels
The basic situation was introduced firstly on the wheel double axis fatigue (abbreviated to WDAF) testing. Then the basic process to carry out the finite element analysis and the fatigue life prediction on the WDAF testing were introduced briefly. Subsequently, a typical wheel was taken as an example to implement the finite element fatigue life prediction for the WDAF testing of the aluminum alloy wheel. Finally, an initial criteria was proposed for the WDAF life prediction based on the analytical results from FEA for several wheels.
Numerical modeling and simulation of wheel radial fatigue tests
Abstract A computational methodology is proposed for fatigue damage assessment of metallic automotive components and its application is presented with numerical simulations of wheel radial fatigue tests. The technique is based on the local strain approach in conjunction with linear elastic FE stress analyses. The stress–strain response at a material point is computed with a cyclic plasticity model coupled with a notch stress–strain approximation scheme. Critical plane damage parameters are used in the characterization of fatigue damage under multiaxial loading conditions. All computational modules are implemented into a software tool and used in the simulation of radial fatigue tests of a disk-type truck wheel. In numerical models, the wheel rotation is included with a nonproportional cyclic loading history, and dynamic effects due to wheel–tire interaction are neglected. The fatigue lives and potential crack locations are predicted using effective strain, Smith–Watson–Topper and Fatemi–Socie parameters using computed stress–strain histories. Three-different test conditions are simulated, and both number of test cycles and crack initiation sites are estimated. Comparisons with the actual tests proved the applicability of the proposed approach.
Botulinum toxin in the management of chronic migraine: clinical evidence and experience
Chronic migraine (CM) is a severely disabling neurological condition characterized by episodes of pulsating unilateral or bilateral headache. The United States Food and Drug Administration (FDA) approved onabotulinumtoxinA (Botox®) for the prophylactic treatment of CM in 2010. It has been shown that onabotulinumtoxinA is effective in the reduction of headache frequency and severity in patients with CM. Treatment is well tolerated by the patients. This review reports on the history of botulinum neurotoxin (BoNT) in CM and presents the current clinical evidence for the use of onabotulinumtoxinA in the treatment of CM.