Background: Although, different grafts are used for nasal tip plasty in cases with under projected or ill defined tip, the selection of a graft material, which provides sufficient amount of tissue with least donor site morbidity and low recipient site complication is challenging. The objectives of the present study were to examine the usefulness of cartilaginous dorsum as a proper material for tip graft, and to introduce the cartilaginous dorsum as an acceptable material for columellar strut.Methods: Fifty six (18 males and 38 females) patients were operated for augmentation tip plasty and hump reduction from 2004 to 2008. The tailored cartilaginous or ostecartilaginous dorsum was used as a tip graft or columellar strut in 35 and 21 cases, respectively. The cartilaginous framework was exposed using open or close rhinoplasty approach in 41 and 15 cases, respectively. The patients were followed for 12- 36 months. Cosmetic outcomes and patients' satisfaction were obtained using qualitative measures.Results: The percentage of patients with very improved, improved, unchanged or unacceptable aesthetic outcome were 39.29%, 50%, 3.57% and 7.14%, respectively. Moreover, the percentages of very satisfied, satisfied, indifferent and unsatisfied patients were 66%, 18%, 9%, and 7%, respectively.Conclusion: The procedure provides a well-defined nasal tip with no evidence of bifidity, angularity, or cartilage graft visibility and displacement. The use of dorsal osteocartilaginous graft offers outstanding advantages including ease of harvest, mould, fix, and low resorption.

The strut-and-tie method can be used for the design of regions of structures where the basic assumptions of flexure theory, namely plane sections remaining plane before and after bending, are not applicable. Such regions occur near force discontinuities arising from concentrated forces or reactions and near geometric discontinuities such as abrupt changes in cross section etc. The strut-and-tie method of design is based on the assumption that appropriate regions in concrete structures can be analysed and designed using hypothetical pin-jointed trusses consisting of struts and ties connected at nodes. Although IS 456:2000 recommends the strut-and-tie method for design of corbels, no guidelines are given for determination of concrete strut and node dimensions and for the allowable stresses for design. The ACI Code 318-02 on the other hand, gives explicit and practical recommendations related to the design of structural members using the strut-and-tie method. To amplify the application of these recommendations to the design of structural concrete a complete example on the analysis and design of a double corbel using the strut-and-tie method has been presented.    

Confined masonry walls (CMWs) are generally used as a suitable type of lateral force resisting systems in earthquake prone regions. The RC confining members (tie-beams) in such walls are mainly used to provide integrity and increase the ductility of masonry buildings. Considering the inherent complexities of the structural behavior of masonry materials and interaction between tie-beams and walls, modeling and analysis of CMWs is one of the challenging problems in the analysis of buildings under lateral loads. Among the building analysis methods, macro-modeling methods have always been considered by researchers due to their proper accuracy and efficiency. The purpose of this study is to modify and verify a suitable macro-model based on the equivalent strut model (Crisafulli infill model) for the cyclic analysis of CMWs. To this end, first, by comparing the behavior of CMWs with infilled frames and identifying their similarities and differences and using the relationships available in the literature, the specifications and parameters of this model are modified for CMWs (with and without openings) as well as CMWs with interior tie-beams. Then, based on the available experimental results of several CMWs and a 3D confined masonry building, the accuracy of the equivalent strut-based model in estimating the lateral stiffness and shear capacity of the specimens is discussed. The results show that it is possible to predict reasonably the overall response of CMWs by the modified equivalent strut model.

Reinforced concrete (RC) members with significant geometric discontinuities and complex stress distributions under loading require considerable analyses and usually complicated reinforcement detailing. Deep beams with large openings are one of the examples. Strut-and-tie models (STM) are a valuable tool for the design of these members. However, the actual stress fields in deep beams with openings are typically different compared with those predicated by STMs, as reported by many experimental investigations. Therefore, an optimization method on homogenization is used for finding optimal strut-and-tie models for RC elements. Previous truss optimization methods are strongly dependent on the element removal ratio and the FE mesh. Additionally, they require many algorithmic parameters to be finely tuned, and their convergence to optimal solution is uncertain. Full homogenization (FH) methods solve most of these problems because of their explicit formulas. Two examples from STM literature are used to illustrate the application of these methods.In the experimental part of the study, two reinforced concrete and two steel fiber reinforced concrete (SFRC) deep beams with opening were manufactured and monotonically loaded up to failure. The design of each test specimen was carried out using optimal truss models and the ACI 318-11 provisions for STM. The structural performance of the specimens is compared with that of some similar specimens in previous test series. All test specimens in this study carried loads greater than the factored design loads. Reinforced concrete specimens using optimization-derived truss models have efficient responses, in terms of ratio of ultimate load to steel weight.

The strut-and-tie method can be used for the design of Disturbed regions (D-regions) of structures where the basic assumption of flexure theory, namely plane sections remaining plane before and after bending, does not hold true. Such regions occur near statical discontinuities arising from concentrated forces or reactions and near geometric discontinuities, such as abrupt changes in cross section etc. The strut-and-tie method of design is based on the assumption that the D-regions in concrete structures can be analysed and designed using hypothetical pin-jointed trusses consisting of struts and ties inter-connected at nodes. Continuous deep beams occur as transfer girders in multi-storey frames, as pile caps and as foundation wall structures etc. The usual design practice for continuous deep beams has been to employ empirical equations, which are invariably based on simple span deep beam tests. Given the unique behavioural pattern of continuous deep beams, this practice is unrealiable. Since continuous deep beams contain significant extents of D-regions and they exhibit a marked truss or tied arch action, the strut-and-tie method offers a rational basis for the analysis and design of such beams. The mechanics and behavior of continuous deep beams are briefly discussed from which a strut-and-tie model for such a beam is developed. A complete example on the analysis and design of a continuous deep beam using the strut-and-tie method is presented. The design has been carried out using the recommendations of the ACI Code 318-02.

Icing on aircraft engine inlet components can impair performance and safety. This study numerically simulates the icing process on a full-scale engine inlet strut under real operating conditions. A modified Shallow-Water Icing Model (SWIM) and an automatic icing type-detection algorithm were employed to predict water film flow and icing phase changes, calculated with a self-developed program. The models' accuracy was validated through comparison of simulated three-dimensional ice shapes on a NACA0012 airfoil with experimental results. Based on this validation, we conducted a numerical analysis of the unsteady icing process of the strut, focusing on the effects of inflow temperature, velocity, and other factors on icing. The results demonstrate that ice horn formation significantly influences ice shape development, with the maximum local water collection efficiency shifting from the stagnation point to the ice horns over time, thereby accentuating the dual-horn characteristic. Inflow velocity impacts icing differently depending on temperature. At -10°C, low velocities produce dual-horn ice, while high velocities yield streamlined ice due to aerodynamic heating, reducing ice thickness at the stagnation point by 18.5%. At -20°C, low velocities result in streamlined ice, whereas high velocities promote dual-horn ice due to higher airflow recovery temperatures, leading to a 121.9% increase in ice thickness at the stagnation point.

This paper presents an ultimate strength analysis of two reinforced and one prestressed concrete deep beams tested to failure. A nonlinear strut-tie model approach implemented with an interactive computer graphics program was utilized to evaluate the ultimate strength and nonlinear behavior of the beams. Different types of strut-tie models for the beams were selected based on the principal compressive stress trajectories, actual specimen detailing, and loading and support conditions. The present study shows that the nonlinear strut-tie model approach can provide simple and effective solutions for a large number of analysis situations by describing the essential structural behavior aspects and evaluating the strength of structural concrete. It also allows for the conceptual representation of the complex concrete and reinforcing steel interactions, and permits the study of localized effects through the bearing capacity evaluation of nodal zones. The framework provided by the nonlinear strut-tie model approach for considering combined actions is strongly suggested in the ultimate strength analysis of structural concrete deep beams.