Local buckling and postbuckling of panels stiffened by stringers and rings and subjected to combined in-plane loads is explored with the use of a single module model that consists of one stringer and a width of panel skin equal to the stringer spacing. The cross-section of the skin-stringer module is discretized and the displacement field is assumed to vary trigonometrically in the axial direct...

BACKGROUND Several strategies to reduce construct stiffness have been proposed to promote secondary bone healing following fracture fixation with locked bridge plating constructs. However, stiffness reduction is typically gained at the cost of construct strength. In the present study, we tested whether a novel strategy for stiffness reduction, termed far cortical locking, can significantly redu...

BACKGROUND Treatment options for comminuted tibial shaft fractures include plating, intramedullary nailing, and external fixation. No biomechanical comparison between an interlocking tibia nail with external fixation by an Ilizarov frame has been reported to date. In the present study, we compared the fatigue behaviour of Ilizarov frames to interlocking intramedullary nails in a comminuted tibi...

Existence of cracks in industrial structures is one of the important causes of their failure, especially when they are subjected to important axial compressive forces that might lead to buckling. Therefore, it must be considered in stress analysis and designing and loading of such structures. In this paper, the buckling and post-buckling behaviors of stainless-steel cracked plates under axial c...

BACKGROUND Angle-stable locking plates have improved the surgical management of fractures. However, locking implants are costly and removal can be difficult. The aim of this in vitro study was to evaluate the biomechanical performance of a newly proposed crossed-screw concept ("Fence") utilizing conventional (non-locked) implants in comparison to conventional LC-DCP (limited contact dynamic com...

Spondyloepiphyseal dysplasia congenita (SED) is a rare form of skeletal systemic disease, characterized by congenital dwarfism with a short trunk and epiphysial dysplasia in the long bones and vertebral bodies. Patients also frequently suffer from atlanto-axial instability due to os odontoideum. Compression of the spinal cord caused by atlanto-axial instability is a common, serious complication...

Because many osteoporotic fractures occur during a fall, understanding the effect of off-axis loads on initiation and propagation of microdamage in trabecular bone should provide further insight into the biomechanics of age-related fractures. Fourteen on-axis cylindrical specimens were prepared from 12 bovine tibiae. Fluorescent stains were used to label the microdamage due to a sequence of com...

The results of a numerical study of the nonlinear response of thin unstiffened aluminum cylindrical shells with a longitudinal crack are presented. The shells are analyzed with a nonlinear shell analysis code that accurately accounts for global and structural response phenomena. The effects of initial crack length on the prebuckling, buckling and postbuckling responses of a typical shell subjec...

Based on tests on six L-shaped RC columns with 500 MPa steel bars, the effect of axial compression ratios and stirrup spacing on failure mode, bearing capacity, displacement, and curvature ductility of the specimens is investigated. Test results show that specimens with lower axial load and large stirrup characteristic value (larger than about 0.35) are better at ductility and seismic performan...

A method for improving the contrast resolution of B-mode images is proposed by combining the speckle reduction technique of frequency compounding (FC), and the coded excitation and pulse compression technique called resolution enhancement compression (REC). FC suppresses speckle but at the expense of a reduction in axial resolution. Using REC the axial resolution and bandwidth of the imaging sy...