Bulletin officiel de la transportation à la Guyane

1903/12 (A1903,N12).

Bulletin officiel de la transportation à la Guyane

1907/03 (A1907,N3).

Bulletin officiel de la transportation à la Guyane

1912/02 (A1912,N2).

Bulletin officiel de la transportation à la Guyane

1912/06 (A1912,N6).

Bulletin officiel de la transportation à la Guyane

1890/02 (N2).

Bulletin officiel de la transportation à la Guyane

1912/03 (A1912,N3).

Bulletin officiel de la transportation à la Guyane

1903/08 (A1903,N8).

Bulletin officiel de la transportation à la Guyane

1890/06 (N6).

Bulletin officiel de la transportation à la Guyane

1907/07 (A1907,N7).

Bulletin officiel de la transportation à la Guyane

1907/12 (A1907,N12).

Bulletin officiel de la transportation à la Guyane

1902.

Bulletin officiel de la transportation à la Guyane

1890/03 (N3).

Bulletin officiel de la transportation à la Guyane

1903/04 (A1903,N4).

Calculation of the critical crack size for cold form rectangular hollow section tube (CRHS) under bending load at -40º C temperature

To predict the capacity of the structure or the point which is followed by instability, calculation of the critical crack size is important. Structures usually contain several cracks but not necessarily all of these cracks lead to failure or reach the critical size. So, defining the harmful cracks or the crack size which is the most leading one to failure provides criteria for structure’s capacity at elevated temperature. The scope of this thesis was to calculate fracture parameters like stress intensity factor, the J integral and plastic and ultimate capacity of the structure to estimate critical crack size for this specific structure. Several three dimensional (3D) simulations using finite element method by Ansys program and boundary element method by Frank 3D program were carried out to calculate fracture parameters and results with the aid of laboratory tests (loaddisplacement curve, the J resistance curve and yield or ultimate stress) leaded to extract critical size of the crack. Two types of the fracture which is usually affected by temperature, Elastic and Elasti-Plastic fractures were simulated by performing several linear elastic and nonlinear elastic analyses. Geometry details of the weldment; flank angle and toe radius were also studied independently to estimate the location of crack initiation and simulate stress field in early stages of crack extension in structure. In this work also overview of the structure’s capacity in room temperature (20 ºC) was studied. Comparison of the results in different temperature (20 ºC and -40 ºC) provides a threshold of the structure’s behavior within the defined range.

Experimental analysis of optimization techniques on the road passenger transportation problem

Analyzing the state of the art in a given field in order to tackle a new problem is always a mandatory task. Literature provides surveys based on summaries of previous studies, which are often based on theoretical descriptions of the methods. An engineer, however, requires some evidence from experimental evaluations in order to make the appropriate decision when selecting a technique for a problem. This is what we have done in this paper: experimentally analyzed a set of representative state-of-the-art techniques in the problem we are dealing with, namely, the road passenger transportation problem. This is an optimization problem in which drivers should be assigned to transport services, fulfilling some constraints and minimizing some function cost. The experimental results have provided us with good knowledge of the properties of several methods, such as modeling expressiveness, anytime behavior, computational time, memory requirements, parameters, and free downloadable tools. Based on our experience, we are able to choose a technique to solve our problem. We hope that this analysis is also helpful for other engineers facing a similar problem