No abstract

This study considered the solution of the stochastic vibration of nonlinear mechanical systems with Gaussian random excitations. It realised a short review of linearisations techniques in stochastic dynamics mainly with application in the area of truss finite element modelling. The presented method of statistical linearisation is applied to numerical testing. In the second part of the article, the sensitivity analysis of the first two stress statistical moments and structural weight minimising subjected to the random stress constrains presented by mean value and standard deviation was brought to the fore. Cross-sectional areas were used as optimising parameters.

No abstract

This article is divided into two parts—in the first part, authors inform about their testing device that enables the acquisition of results from uniaxial and multiaxial fatigue tests (the bending−torsion combination). We present the approaches used during designing and building the testing device. The direct implementation of the research in the second part will concentrate on implementing the acquired results for the frame design of a vehicle worked out by the authors. The three-wheeled vehicle has the front steered wheel suspended in an unconventional way. This original design can cause an increased load on the vehicle’s frame. This can be apparent mainly during driving through curves. Therefore, the fatigue curves of the tested material (EN AW 6063) will be implemented from the point of view of its usability in operation. A vehicle frame is most often loaded by bending and torsion. The authors assess the influence of welding on the fatigue life of this unique unconventional vehicle by determining the fatigue curves of the material for its production. The stresses achieved on the test specimens fully correspond to the load of the frame (in welds) during its operation.

No abstract