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Dual-phase (DP) steels are becoming more and more popular for automotive applications. They offer a weight reduction with a combination of energy absorption for crash zones. Rails, reinforcements, back panels, cross members, and pillars can be given as application examples. DP steels microstructure consists of a soft ferrite with hard martensite. The martensite provides strength while the ferrite provides ductility. The strength level of DP steel is correlated with the martensite fraction in the microstructure, and the fraction of martensite can be controlled via intercritical annealing. In this work, thermodynamic analysis of St52 steel was carried out with Thermo-Calc software. A1 and A3 temperatures were determined by calculating the temperaturedependent phase fractions. Intercritical annealing temperatures were determined according to the calculated critical temperatures (A1 and A3). The intercritical annealing process was modelled by using Simheat NxT software. In this modelling and simulation study, the intercritical annealing temperature impact on the final microstructure and hardness of DP steel was investigated. [ABSTRACT FROM AUTHOR]

In this study, the angle of twist of axially layered functionally graded circular hollow shafts subjected to a twisting torque at the free end was analyzed under clamped-free boundary conditions using finite element software ANSYS. The hollow shafts were made using three layers including various mixtures of ceramic and metal materials. Layer locations on the shafts were performed using L9 orthogonal array based on Taguchi Method. The layer combination with optimum levels was obtained using analysis of the signal-to-noise (S/N) ratio. Significant layers and their percent effects on the angles of twist were analyzed using analysis of variance (ANOVA). According to results obtained, the increase of the ceramic material in layers leads to the decrease of the angle of twist of the beams. The most meaningful layers on response were obtained as first layer with 52.83% effect ratio, second layer with 29.41% effect ratio, and third layer with 17.76% effect ratio. [ABSTRACT FROM AUTHOR]

One of the major problems in hip replacement surgery is the hip replacement loosening. Hip replacement loosening occurs over time after the surgery and it is related to the discretization between the bone cement and prosthesis. The underlying factors of this situation are the stress occurring in the bone cement and the shape of the prosthesis. In this study, cortical and trabecular layers of the femur, bone cement and prosthesis were modeled. The models of bone cement and prosthesis were constructed parametrically and two different sinusoidal formed prostheses were developed unlike the former prostheses shapes. Analyses were conducted for these two different sinusoidal forms by using finite element method and optimization was conducted to obtain the appropriate prosthesis stem shape and bone cement thickness by using parametric modeling in finite element analyses. For finite element analyses and optimization, Ansys Workbench software was used and analyses were conducted for 316LS stainless steel material. Finally, the optimum prosthesis stem shape and bone cement thickness was determined by using the results of the analyses in the first stage. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate the stresses occurred on hard and soft bones after recovering the deficiency caused by totally edentulous and damaged mandible by using abutments with different lengths and prosthesis filling material. Two different damaged parts of 2.5 and 4.5 mm in depth were created with the aid of Solidworks program on the right hand side of the mandible. Implants were then applied between the foremen channels. Later, the damaged models were recovered by abutment with different lengths as for the first method. Two models using abutment were, therefore, obtained for the damaged parts of 2.5 and 4.5 mm in depth. In the second method, for the same damaged cases, prosthesis filling material was used to recover deficiency keeping the abutment length constant. Finally, there were totally obtained 4 different damaged models of two fixed with abutment and two fixed with filling material and 1 undamaged model. At the second step of this study, the stress values were obtained on lower jaw bones by using finite element method under the maximum chewing force and compared to each other. The results showed that stress data obtained particularly on the soft and hard bones were distributed more uniformly on the damaged models fixed with prosthesis filling material compared to the damaged models recovered by abutment. Moreover, the stress values obtained for models fixed with different abutment length were rather high in comparison to those of the filling material application. [ABSTRACT FROM AUTHOR]