Search Results (2)

This paper aims to study the mechanical and electrical properties of the composite structure of PVC film and film cell under biaxial tension. The saddle PVC membrane structure with thin-film battery was obtained by biaxial tensile tests carried out on the composite structure along the fiber direction and at an angle of 45 degrees to the fiber, respectively. The deformation of the film cell and PVC membrane materials was tested using digital image technology, and the voltage of the film cell was tested using a multimeter. The results showed that the tensile strain occurred in both membrane batteries and PVC membrane at different loading levels, and the former was always less than the latter. At a tensile load with the ultimate load ratio of 60%, it was only at the film cell’s outer edge that the stripping occurred. Under the illumination of a stable light source, the film cell voltage decreased gradually with the increasing tensile load. No more than 10% of the cell voltage drop occurred when the membrane material, the principal tensile strain of the cell, and the cell’s expansion area ratio were less than 3.1%, 2.8%, and 1.03, respectively. The experimental results show that the film cell can be applied to the saddle membrane structure by controlling the appropriate load. Full article

An aortic aneurysm is a lethal arterial disease that mainly occurs in the thoracic and abdominal regions of the aorta. Thoracic aortic aneurysms are prevalent in the root/ascending parts of the aorta and can lead to aortic rupture resulting in the sudden death of patients. Understanding the biomechanical and histopathological changes associated with ascending thoracic aortic aneurysms (ATAAs), this study investigates the mechanical properties of the aorta during strip-biaxial tensile cycles. The loss factor—defined as the ratio of dissipated energy to the energy absorbed during a tensile cycle—the incremental modulus, and their anisotropy indexes were compared with the media fiber compositions for aneurysmal (n = 26) and control (n = 4) human ascending aortas. The aneurysmal aortas were categorized into the aortas with bicuspid aortic valves (BAV) and tricuspid aortic valves (TAV). The strip-biaxial loss factor correlates well with the diameter of the aortas with BAV and TAV (for the axial direction, respectively, R² = 0.71, p = 0.0022 and R² = 0.54, p = 0.0096). The loss factor increases significantly with patients’ age in the BAV group (for the axial direction: R² = 0.45, p = 0.0164). The loss factor is isotropic for all TAV quadrants, whereas it is on average only isotropic in the anterior and outer curvature regions of the BAV group. The results suggest that loss factor may be a useful surrogate measure to describe the histopathology of aneurysmal tissue and to demonstrate the differences between ATAAs with the BAV and TAV. Full article