Ergonomic design of the workplace is a matter of utmost importance. Ergonomics should consider reducing the high number of accidents as well as the high amounts paid for insurance. In recent years there have been numerous injuries due to cumulative trauma or due to psychological, sociological and ethical factors. Operators often adapt to improper work conditions, but the number of accidents increases and productivity decreases. The driver of the vehicle must be provided with a suitable space and position so that his posture is physiologically comfortable, does not cause excessive fatigue and illness, there is freedom of movement to drive the steering wheel, steering levers and pedals, which must be accessible and placed in such a way that the driver’s requirements are minimal and the visibility is ensured. In the paper there will be presented elements for the ergonomic design of the workplace for the motor vehicle occupation and will be taken into account several factors involved among which we mention the correct positioning of the seat adjustment while driving a car, adjusting the backrest and seat, adjusting the lumbar support, adjusting the steering position, adjusting the headrests to ensure that in the event of an accident, the risk of a head injury is very small.

MATEC Web of Conferences, open access proceedings in Materials science, Engineering and Chemistry

There are many welded structures in the world such as bridges and viaducts that are subject to fatigue. Some of these structures, generally made of non-alloy or low-alloy steels, have been put into operation many years ago and have accumulated a large number of variable load cycles over time. For this reason, the occurrence of the fatigue phenomenon is inevitable and consists in the occurrence of failures at stresses applied to the structure, below the yield limit of the material. These stresses under the static loads would not cause the failures to appear. This paper will investigate if the ecological reconditioning techniques “weld toe grinding” and “WIG re-melting weld toe,” influence favourably the behaviour of the welded structures made from HSLA steel, in static and variable loads, if the application of these techniques is justified in both cases and finally which is the environmental impact of applying these techniques. In the paper we will present the chemical composition and mechanical properties of the base and filler materials, micro and macrostructures, graphics with the variation of the micro-hardness, we will perform static and fatigue tensile tests and we will rise the durability curve in the case of the fatigue tests. We will also present a mathematical computational algorithm, which highlights the extent to which these ecological rehabilitation techniques pollute the environment. It is more efficient both for technological and ecological reasons to recondition a product than to manufacture it from the very beginning.

The role of the welding seam is to achieve the non-removable joint between two or more parts. In principle, three geometric profiles of the welding seams can be obtained: straight profile; concave profile and convex profile. In practice, this geometric shape of the weld seam profile is very important, both in terms of the resistance of the joint to static stresses and in terms of its fatigue life. There are many factors that can influence the geometric shape of the weld seam: the welding process; welding regime; the nature of the filler materials used, the rehabilitation techniques applied and others. Often, this geometric shape of the weld bead is neglected, which is particularly dangerous due to the fact that an improper geometric shape can generate low mechanical strength in static loads or poor fatigue strength in variable loads. An optimum of the geometric configuration of the welding must be found, which reconciles both situations: the mechanical resistance in case of static stresses and also the fatigue resistance in case of variable loads. In this paper, an analysis will be made with finite elements for the straight and convex profile of the welding seams in the case of fillet welds subjected to fatigue. Several elements will be considered such as: damage; total deformation; fatigue sensitivity versus loading history; equivalent von Misses stress; safety factor.

There are many welded structures in the world such as bridges and viaducts that are subject to fatigue. These structures, generally made of non-alloy or low-alloy steels, have been put into operation some of them with many years ago and have accumulated a large number of variable load cycles over the time. For this reason the occurrence of fatigue phenomenon is inevitable and consists in the occurrence of failures at stresses applied to the structure, below the yield limit of the material. These stresses under the static loads would not cause the failures to appear..This paper will investigate whether two reconditioning techniques “weld toe grinding” and “WIG remelting weld toe”, influences favorably the behavior of welded structures made from HSLA steel, in static and variable loads and therefore if the application of these techniques is justified in both cases. In the paper will be presented the chemical composition and mechanical properties of the base and filler materials, micro and macrostructures, graphics with the variation of microhardness, static and fatigue tensile tests will be performed, and it will be rised durability curve in case of fatigue tests.

Fatigue of the welded joints is a complex phenomena on widely debated in the worldwide literature. The phenomenon of fatigue of welded structures consists in the occurrence of failures in the case of variable loads, where the load varies between a certain maximum and a minimum values, when always the stress level is below the yield limit of the material. In practice, this type of stresses is encountered in the case of bridges in the welded structure, which has numerous cruciform fillet joints. The paper aims is to study how those two welding rehabilitation techniques "weld toe grinding" and "WIG remelting weld toe ", influence the fatigue life time of some cruciform fillet welded samples, by modifying the stress concentrators and the geometrical shape of the welding seam. It has been chosen to study the cruciform fillet welded joint, because on the one hand this type of joint is met very often in case of bridges welded structures and on the other hand it represents the welded joint with the highest susceptibility to occurrence of the defects and implicitly of the failures. The welding procedure used for welding the cruciform fillet welds is MAG (welding with shielded gas protection). The welded samples were welded in a vertical position.