A low-energy acetabular fracture, as a result of falling from standing height, is common among elderly patients and the number of cases is increasing rapidly in developed countries. Several biomechanical factors contribute to the incidence, severity, and type of acetabular fractures, such as body configuration at the impact moment or bone and soft-tissue quality. The current parametric study developed a comprehensive finite element model of the pelvic girdle and simple representation of the whole body and investigated the effects of impact velocity, conventional indoor/outdoor flooring material, and trochanteric soft-tissue stiffness on an acetabular fracture. Our results show that whereas the impact velocity has a substantial influence on the incidence and type of acetabular fracture, the effects of conventional flooring materials and trochanteric soft-tissue quality are not remarkable. It seems that other factors such as the quality of bone (healthy vs. osteoporotic), the thickness of trochanteric soft-tissue, and body configuration at the impact are more critical in the occurrence and type of the acetabular fracture. These results can be valuable in the prevention of acetabular fractures and the design of protective measures such as hip pads or novel flooring materials.

In this paper, an innovative and efficient sandwich panel is proposed for the structural walls for quickly assembled post-disaster housing, as well as load bearing panels for pre-fabricated modular construction and semi-permanent buildings. This study focuses on the flexural and shear behavior of the innovative sandwich panels, which is composed of two 3-D high density polyethylene (HDPE) skins, and high-density Polyurethane (PU) foam core. An experimental study was carried out to validate the effectiveness of this panel for increasing the ultimate bending strength. A series of experimental tests were performed on medium-scale specimens to characterize their core shear behavior. Then, some supplementary tests were run to determine the panels' flexural and shear stiffness. The numerical and experimental investigations show that the 3-D-HDPE sheets, manufactured with a studded surface; considerably enhance the pull-out and delamination strength. Good agreement has been observed between the numerical and experimental tests.

Cardiovascular diseases take many lives yearly and carotid atherosclerosis disease is responsible of a significant portion of cardiovascular deaths. Carotid atherosclerosis disease is a multi-aspects disease and only by considering all of its aspects, a comprehensive insight can be achieved whereas near all of researchers which have been conducted to study, cover only one or two aspects of carotid atherosclerosis disease. Current review by summarizing and categorizing of 77 selected literatures which were published in different scopes of carotid atherosclerosis disease, have attempted to present a comprehensive and succinct source for further studies and fill the gap between carotid atherosclerosis disease aspect by presenting them coincidently. In this review, usage of common diagnostic methods such as ultrasonography and magnetic resonance imaging in carotid atherosclerosis disease detection have been discussed. Also, Current review shows that carotid atherosclerosis disease is product of combination of biochemical, biomechanical, diseases and human health-related risk factors. Also, high concentration of low density lipoprotein seems to be carotid atherosclerosis disease trigger. In addition, carotid atherosclerosis disease simulations indicate that regions which are prone to carotid atherosclerosis disease are associated with low and oscillatory wall shear stress and recirculation zone. It appears that collaboration of different scopes of carotid atherosclerosis disease can lead to outstanding results and using realistic data in carotid atherosclerosis disease studies leads to more accurate results.

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Purpose The incidence of acetabular fractures due to low-energy falls is increasing among the geriatric population. Studies have shown that several biomechanical factors such as body configuration, impact velocity, and trochanteric soft-tissue thickness contribute to the severity and type of acetabular fracture. The effect of reduction in apparent density and elastic modulus of bone as well as other bone mechanical properties due to osteoporosis on low-energy acetabular fractures has not been investigated. Methods The current comprehensive finite element study aimed to study the effect of reduction in bone mechanical properties (trabecular, cortical, and trabecular + cortical) on the risk and type of acetabular fracture. Also, the effect of reduction in the mechanical properties of bone on the load-transferring mechanism within the pelvic girdle was examined. Results We observed that while the reduction in the mechanical properties of trabecular bone considerably affects the severity and area of trabecular bone failure, reduction in mechanical properties of cortical bone moderately influences both cortical and trabecular bone failure. The results also indicated that by reducing bone mechanical properties, the type of acetabular fracture turns from elementary to associated, which requires a more extensive intervention and rehabilitation period. Finally, we observed that the cortical bone plays a substantial role in load transfer, and by increasing reduction in the mechanical properties of cortical bone, a greater share of load is transmitted toward the pubic symphysis. Conclusion This study increases our understanding of the effect of osteoporosis progression on the incidence of low-energy acetabular fractures. The osteoporosis-related reduction in the mechanical properties of cortical bone appears to affect both the cortical and trabecular bones. Also, during the extreme reduction in the mechanical properties of bone, the acetabular fracture type will be more complicated. Finally, during the final stages of osteoporosis (high reduction in mechanical properties of bone) a smaller share of impact load is transferred by impact-side hemipelvis to the sacrum, therefore, an osteoporotic pelvis might mitigate the risk of sacral fracture.

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Connections represent major challenges in the design of composite structures, mainly because they entail discontinuities in the geometry of the structure and material properties, and introduce high local stress concentrations. Despite some constructability complications, integrated connection could be a reliable solution. In this paper, the structural behaviour of an integrated connection for implementation between adjacent composite sandwich panels in rapid assembly buildings is studied. The integrated connection system consists of 3-D high density polyethylene (HDPE) skin faces, and cores of high-density polyurethane (PUR) foam integrated into the sandwich panels at the moment of their production. The study included experimental investigations regarding the mechanical and structural response of the connection under actual applied loads, and its torsional rigidity, rotational stiffness and behaviour under lateral loading is investigated. Using Finite Element modelling, the stress distribution and the mechanisms of failure are studied. The results show a good agreement between the numerical and experimental results.

Cardiovascular diseases takes many lives yearly, whereas atherosclerosis is on the top. Carotid atherosclerosis disease considered as a multi-aspects disease and only by considering all of its aspects, a comprehensive insight can be achieved. It seems that wall motion has great effects on arterial hemodynamics and Low Density Lipoprotein (LDL)mass transport and concentration while LDL concentration is believed to be highly associated with atherosclerosis plaque formation. The primary goal of this study is to investigate the wall elasticity effects on carotid hemodynamics and LDL mass transport through carotid artery bifurcation as a challenging case due to its geometry and location. The blood is modeled as Carreau fluid which is considered as a well-behavior model for blood. A pulsatile speed profile applied as the inlet boundary and two-ways Fluid Structure Interaction (FSI) transient analysis is performed to achieve more accurate. In order to investigate wall elasticity effects, the carotid bifurcation modeled as solid, linear elastic and hyperelastic (Mooney-Rivlin). As the high LDL concentration can be considered as atherogenes is region indicator, therefore, it is used as the criterion for assessing the different arterial wall assumption. The wall elasticity effects on the hemodynamics are presented in three-time steps; early systole, end systole and end diastole. Results show that linear elastic and hyperelastic models predict very alike flow pattern however wall deformation and behavior are totally different. Results indicatet hat solid wall assumption is not appropriate for large and complicated arteries such as carotid bifurcation. Hyperelastic model (Mooney-Rivlin) seems more relevant and one the second place, the linear wall elastic model may be a good choice.