Improving programming skills of Mechanical Engineering students by teaching in C# multi-objective optimizations methods

Designing an optimized suspension system that meet the main functions of comfort, safety and handling on poor quality roads is a goal for researchers. This paper represents a software development guide for designers of suspension systems with less programming skills that will enable them to implement their own optimization methods that improve traditional methods by using their domain knowledge.

Computer Simulation Paradigm Regarding the Structure and Mechanical Characteristics of Human Long Bones

Given the complex form of the long bones, a quality method of geometrical modeling which provides a good result is that of the 3D modeling by reconstruction, using the principles of reverse engineering. One of the important problems that shall be taken into consideration while modeling is the one concerning the real structure of the bones. This aspect presents a lot of importance because from the point of view of the mechanical behavior, the bones are neither homogenate structures. In this paper a study of the long bones structures is undergone, and in relation to the modelated element (the human tibia) it is divided in areas (called constructive-anatomical entities) of different mechanical…

The experimental study of the hybrid fixation in ACL reconstruction

Abstract The article is approaching an interesting topic regarding ACL reconstruction using the hamstring tendons (semitendinosus and gracilis) as the graft. The initial graft fixation after ACL reconstruction is mechanical and it must assure the stability of the system until the biologic integration takes place. No fixation system is as strong as the native ACL insertion. Therefore, hibrid fixation like an improvement of simple fixation is a field worth studying. The fixation shown in this article is the Hybrid fixation consisting of direct fixation with interference screw and an extra cortical fixation over a cortical screw.

Studies on predictive virtual models based on finite element analysis of the behaviour of geomembranes

The study shown in this paper presents the behaviour of geomembranes used at the ecological landfills. For this goal was used a method designed to elaborate the virtual models of 3D geomembrane with one ply or 2 plies disposed at 30°, 45° and 90° and based on this model there were developed a number of 20 particular cases. For each situation it was realized the nonlinear analyses for all the developed cases with different vertical pressures representing different loads for the waste layer (1m, 2m, 10m, 15m, 20m). The main results are obtained in graphical form and represent the Maximum tensions Von Mises and total displacements of the geomembrane.

Studies of the Solar Radiations' Influence About Geomembranes Used in Ecological Landfill

Abstract The study shown in this paper presents the behavior of geomembranes used at the ecological landfills. The influences of the solar radiations has a great importance regarding the correct mounting of the geomembranes. The mathematical model developed for the determination anytime and anywhere in the world for the next values and parameters: apparent solar time, solar declination, solar altitude, solar azimuth and incidence angle, zone angle, angle of sun elevation, solar declination, solar constant, solar flux density, diffuse solar radiation, global radiation, soil albedo, total radiant flux density and relational links of these values. The results of this model was used for creatio…

Sizing and shape optimization material use in 10 bar trusses

Truss optimization has the goal of achieving savings in costs and material while maintaining structural characteristics. In this research a 10 bar truss was structurally optimized in Rhino 6 using genetic algorithm optimization method. Results from previous research where sizing optimization was limited to using only three different cross-sections were compared to a sizing and shape optimization model which uses only those three cross-sections. Significant savings in mass have been found when using this approach. An analysis was conducted of the necessary bill of materials for these solutions. This research indicates practical effects which optimization can achieve in truss design.

Designing a Specialized Devices for Correction of the Axis Deviation at the Human Leg

The presented article is an original contribution which implies the design of a specialized device for high tybial osteotomy (HTO) optimization. In the papers are presented the sources that imply HTO, the axial deviations of the human lower member from the correct position. This sources are the gonarthosys owed to the usage of the knees cartilages or owed to some diseases (such as the Blount disease) and the vicious consolidated fractures. After presenting the needs to realize such a specialized device for HTO, the principal requests the device shall fulfill are underlined. Starting from these , two sub ensembles were projected, one for the tibial positioning and for the execution of the ho…

Customizable Patient-Specific Cutting Guide for High Tibial Osteotomy

Abstract The paper is an interdisciplinary medical and engineering approach that aims to optimize the accuracy of the High Tibial Osteotomy surgical intervention. The axial deviations of the human inferior limb are presented in the first part of the paper. Without altering the shape of the bones, these deviations cause the wear of the knee’s articular cartilage by gonarthrosis. One of the most common and effective treatment modalities for eliminating axial deviations is High Tibial Osteotomy. Because the surgical procedure involves 3D spatial bone cutting, the accuracy of the procedure and thus the success of the operation and the recovery of the patient is dependent on the execution of the…

Determining efficiency of cycloid reducers using different calculation methods

Cycloid reducers are gear trains which can be classified as planetary transmissions. These transmissions have a very wide range of uses in industry in transporters, robots, satellites, etc. This research presents a comparative analysis of three analytical methods for determining cycloid drive efficiency. The paper explores every mathematically formulated method and compares them to experimental results from literature. The presented methods for determining efficiency have a common property, in that they all determine losses due to friction on the bearing cam surface of the shaft, the rollers of the central gear and the output rollers. The calculation of efficiency values is done for standar…

Modular device used in the surgery of the human tibia

The influence of the cycloid disc bearing type on the cycloidal speed reducer efficiency

The robotics industry has experienced a rapid expansion in the last decade. As a result, the market of speed reducers with high gear ratios, high precision and a compact design is growing rapidly. In addition to these characteristics, it is very important for gear trains to have high efficiency. Because of their compact design, cycloidal speed reducers are not exposed to axial forces, which is their important characteristic. This means that radial bearings can be used in their supports. The bearing type has significant effects not only on the design and dimensions of the cycloid speed reducer but also on its efficiency. In this paper, an analysis of power losses for different types of rolli…

Experimental modular stand used for studies of the High Tibial Osteotomy

The optimization of the surgery strategies for the correction of the axial deviations of the human lower member presents a great importance both for the affected patients and for surgeons. This article seeks to develop a modular stand used mainly for experimental study of the High Tibial Osteotomy (HTO). In the article it is also shown the relation between the axial deviations of the human leg and their corrections using HTO. The modular devices were designed, executed and used in the experimental research.