Influence of the edge rounding process on the behaviour of blanked parts: numerical predictions with experimental correlation

Blanking of sheet metal is an important forming process in the automotive industry for the manufacture of mechanical components. The final component shape, obtained at the end of bending or deep-drawing processes, often has sharp edges due to the blanking operation. Concerning passenger safety components, like seat belt anchors, rounding of the edges by punching is necessary to avoid cutting the belt material. In addition to removing the sharp edges, the punching results in work hardening of the material in the rounded zones which results in an increase in the local resistance of the material. In this study, a high-strength low-alloy steel (HSLA S500MC) has been tested with the aim of quantifying the blanking and edge rounding operations. The mechanical behaviour of test specimens is investigated by means of tensile tests and the material is characterised in terms of Vickers micro-hardness. Numerical simulations of the edge rounding process are developed using previously identified material behaviour laws. The residual stress fields are characterised and compared to experimental results. This is done so that numerical simulation can be done in the future to prediction the in-service behaviour of the component. Specimens with rounded edges are compared to specimens that were not submitted to the rounding operation. It is shown that Edge Rounding by Punching improves the component resistance, therefore justifying the use of this process in the manufacture of automotive safety components

Safety part design optimisation based on the finite elements method and a genetic algorithm

This paper deals with a numerical approach for improving the mechanical properties of a safety belt anchor by optimizing its shape and the manufacturing process by using a multi-objective genetic algorithm (NSGA-2). This kind of automotive component is typically manufactured in three stages: blanking, rounding of the edges by punching and finally bending (90°). This study focuses only on the rounding and bending processes. The numerical model is linked to the genetic algorithm (GA) in order to optimize the shape of the part and the process parameters. This is implemented by using ABAQUS© script files developed in the Python programming language and CATIA© script files in VBScript. The algorithm modifies the part’s design parameters in the CAD system, imports the model in STEP format into ABAQUS CAE and starts the Finite Elements Analysis (FEA) automatically. The material behaviour is modelled using a specific Lemaitre material damage formulation implemented in ABAQUS© via a FORTRAN user subroutine. The influence of two process parameters (the die radius and the rounding punch radius) and five shape parameters on the component behaviour is investigated. The search for the optimum component design depends on three objective functions which are (i) the material damage state at the end of the forming process, (ii) the von Mises stress field and (iii) the maximum von Mises stress in the folded zone. A global optimisation is finally performed in order to improve the ultimate unbending load and the volume of the safety part. This work has two major areas of innovation: (a) the improvement of the genetic algorithm NSGA-2; and (b) the development of an integrated numerical procedure including “Computer aided design” and “mechanical finite element simulation” controlled by the genetic algorithm.DEVILL

Prise en charge précoce de la dysfonction érectile après prostatectomie totale (à propos de 42 cas)

LILLE2-BU Santé-Recherche (593502101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Enhanced Resonant Raman Scattering of GaN Functional Layers Using Al Thin Films - A Versatile Tool for Multilayer Structure Analysis

International audienceIn order to selectively analyze active thin layers close to surface in power devices structures, Raman scattering is necessary with UV excitation. However, the Raman spectra of GaN are usually affected by the direct bandgap photoluminescence of the material, which interferes with the Raman measurements and decreases the quality and resolution of the Raman spectra. In this work, we demonstrate experimentally that nanostructured aluminum films deposed on GaN epitaxial layers decrease the influence of the photoluminescence on the resonant Raman spectra and increase its overall spatial resolution under UV illumination

Laparoscopic sentinel lymph node dissection in prostate cancer patients: the additional value depends on preoperative data

International audienceAim In intermediate- or high-risk prostate cancer (PC) patients, to avoid extended pelvic lymph node dissection (ePLND), the updated Briganti nomogram is recommended with the cost of missing 1.5 % of patients with lymph node invasion (LNI). Is it possible to reduce the percentage of unexpected LNI patients (nomogram false negative)? We used the isotopic sentinel lymph node (SLN) technique systematically associated with laparoscopic ePLND to assess the potential value of isotopic SLN method to adress this point. Methods Two hundred and two consecutive patients had procedures with isotopic SLN detection associated with laparoscopic ePLND for high or intermediate risk of PC. The area under the curve (AUC) of the receiver operating characteristics (ROC) analysis was used to quantify the accuracy of different models as: the updated Brigantinomogram, the percentage of positive cores, and an equation of the best predictors of LNI. We tested the model cutoffs associated with an optimal negative predictive value (NPV) and the best cutoff associated with avoiding false negative SLN detection, in order to assist the clinician’s decision of when to spare ePLND. Results LNI was detected in 35 patients (17.2 %). Based on preoperative primary Gleason grade and percentage of positive cores, a bivariate model was built to calculate acombined score reflecting the risk of LNI. For the Briganti nomogram, the 5 % probability cutoff avoided ePLND in 53 % (108/202) of patients, missing three LNI patients (8.6 %), but all were detected by the SLN technique. For our bivariate model, the best cutoff was <10, leaving no patient with LNI due to positive SLN detection (four patients= 11.4 %), and avoiding ePLND in 52 % (105/202) of patients. Conclusion For patients with a low risk of LNI determined using the updated Briganti nomogram or bivariate model, SLN technique could be used alone for lymph node staging in intermediate- or high-risk PC patients

Radical Prostatectomy after Vascular Targeted Photodynamic Therapy with Padeliporfin: Feasibility, and Early and Intermediate Results

PURPOSE: Vascular targeted photodynamic therapy with TOOKAD® is a new therapeutic option for localized prostate cancer management. The objectives of this study were to assess the feasibility of radical prostatectomy after vascular targeted photodynamic therapy and describe functional and oncologic outcomes. MATERIALS AND METHODS: We retrospectively included in study 45 patients who underwent salvage radical prostatectomy after vascular targeted photodynamic therapy for recurrent prostate cancer at a total of 14 surgical centers in Europe between October 2008 and March 2017. Of the 42 radical prostatectomies performed 16 were robot-assisted, 6 were laparoscopic and 20 were open surgery. Primary end points were morbidity and technical difficulties. Secondary end points were early and intermediate postoperative functional and oncologic outcomes. RESULTS: Median operative time was 180 minutes (IQR 150-223). Median blood loss was 200 ml (IQR 155-363). According to the surgeons the surgery was easy in 29 patients (69%) and difficult in 13 (31%). Nerve sparing was feasible in 14 patients (33%). Five postoperative complications (12%) were found, including 2 Clavien I, 2 Clavien II and 1 Clavien IIIB complications. Of the cases 13 (31%) were pT3 and 21 (50%) were pT2c. Surgical margins were positive in 13 patients (31%). Prostate specific antigen was undetectable at 6 to 12 months in 37 patients (88%). Nine patients underwent complementary radiotherapy. Four patients had final prostate specific antigen greater than 0.2 ng/ml at a median followup of 23 months (IQR 12-36). At 1 year 27 patients (64%) were completely continent (no pads) and 10 (24%) had low incontinence (1 pad). Four patients (11%) recovered potency without treatment and 23 (64%) recovered potency with appropriate treatment. CONCLUSIONS: Salvage radical prostatectomy after vascular targeted photodynamic therapy treatment was feasible and safe without difficulty for most of the surgeons.status: publishe

Radical Prostatectomy after Vascular Targeted Photodynamic Therapy with Padeliporfin: Feasibility, and Early and Intermediate Results

[Purpose] Vascular targeted photodynamic therapy with TOOKAD® is a new therapeutic option for localized prostate cancer management. The objectives of this study were to assess the feasibility of radical prostatectomy after vascular targeted photodynamic therapy and describe functional and oncologic outcomes.[Materials and Methods] We retrospectively included in study 45 patients who underwent salvage radical prostatectomy after vascular targeted photodynamic therapy for recurrent prostate cancer at a total of 14 surgical centers in Europe between October 2008 and March 2017. Of the 42 radical prostatectomies performed 16 were robot-assisted, 6 were laparoscopic and 20 were open surgery. Primary end points were morbidity and technical difficulties. Secondary end points were early and intermediate postoperative functional and oncologic outcomes.[Results] Median operative time was 180 minutes (IQR 150-223). Median blood loss was 200 ml (IQR 155-363). According to the surgeons the surgery was easy in 29 patients (69%) and difficult in 13 (31%). Nerve sparing was feasible in 14 patients (33%). Five postoperative complications (12%) were found, including 2 Clavien I, 2 Clavien II and 1 Clavien IIIB complications. Of the cases 13 (31%) were pT3 and 21 (50%) were pT2c. Surgical margins were positive in 13 patients (31%). Prostate specific antigen was undetectable at 6 to 12 months in 37 patients (88%). Nine patients underwent complementary radiotherapy. Four patients had final prostate specific antigen greater than 0.2 ng/ml at a median followup of 23 months (IQR 12-36). At 1 year 27 patients (64%) were completely continent (no pads) and 10 (24%) had low incontinence (1 pad). Four patients (11%) recovered potency without treatment and 23 (64%) recovered potency with appropriate treatment.[Conclusions] Salvage radical prostatectomy after vascular targeted photodynamic therapy treatment was feasible and safe without difficulty for most of the surgeons