Plate Stability Verifications of Aluminium Plate Girders

The paper focuses on overall and local web plate buckling of longitudinally multi-stiffened aluminium plate girders subjected to compression, bending, shear and transverse loading. The authors completed wide-range bifurcation stability analysis by energy method. Based on the results of the completed parametric study, buckling coefficients are formulated, taking also into account the possible interaction of local and overall buckling. Modifications are proposed for the standard Eurocode calculations of critical loads. Modification in resistance calculation for web crippling is also proposed to take the beneficial effect of curved flange-to-web connection into account. Numerical model is developed for nonlinear static analysis. Virtual experimenting – considering actual material behaviour and imperfections – is invoked for the calibration of the model.

Construction and Biomechanical Properties of PolyAxial Self-Locking Anatomical Plate Based on the Geometry of Distal Tibia

In order to provide scientific and empirical evidence for the clinical application of the polyaxial self-locking anatomical plate, 80 human tibias from healthy adults were scanned by spiral CT and their three-dimensional images were reconstructed using the surface shaded display (SSD) method. Firstly, based on the geometric data of distal tibia, a polyaxial self-locking anatomical plate for distal tibia was designed and constructed. Biomechanical tests were then performed by applying axial loading, 4-point bending, and axial torsion loading on the fracture fixation models of fresh cadaver tibias. Our results showed that variation in twisting angles of lateral tibia surface was found in various segments of the distal tibia. The polyaxial self-locking anatomical plate was constructed based on the geometry of the distal tibia. Compared to the conventional anatomical locking plate, the polyaxial self-locking anatomical plate of the distal tibia provides a better fit to the geometry of the distal tibia of the domestic population, and the insertion angle of locking screws can be regulated up to 30°. Collectively, this study assesses the geometry of the distal tibia and provides variable locking screw trajectory to improve screw-plate stability through the design of a polyaxial self-locking anatomical plate.

VIBRATION AND STABILITY OF A HEAVY AND HEATED VERTICAL CIRCULAR PLATE

This paper is concerned with the vibration and stability of a standing, heavy, and circular plate when heated. This investigation also deals with the plate being exposed to inertial forces due to uniform acceleration. The plate edge is clamped. Natural frequencies of transverse vibrations depending on the plate weight and temperature were determined using the Galerkin's method. Mode shapes are given for some frequencies including the influence of weight parameter on changes in mode shapes. It is shown that frequencies split for the asymmetric mode shapes, so that there are two different frequencies in those cases. Critical weight parameter values where plate stability ceases were determined. Critical values of the weight parameter depending on Poisson's ratio are also presented herein.