Non-typical Hazards in Road Traffic

The authors describe a road traffic accident with an unusual cause which was a wrong defensive reaction of the driver on the road surface covered with spilled grain. The results of road tests are presented illustrating behaviour of the vehicle on the road surface in such conditions. Attention is paid to the psychological aspect of the drivers defensive reactions in the situation when they are taken aback with non-typical road surface conditions. There is a need to train drivers in right decision making skills (psychology) and in the ability to make effective defensive manoeuvres (driving technique) in order to improve road traffic safety.

Website: http://www.arjonline.org/engineering/american-research-journal-of-mechanical-and-automation-engineering/

Comparison of Different Simulation Approaches in Ring-Core Method

Ring-Core, a semi-destructive method enables measurement of the residual stresses inside the material by the sensor attached at the top of the specimen. Such stress reconstruction requires proper determination of the calculation coefficients. Thus the simulation model for finite elements analyzes is created by means of two different commercial software. Subsequently both simulation results are compared experimentally by measurement on the specimen loaded by known uniaxial state of stress.

Website: http://www.arjonline.org/engineering/american-research-journal-of-mechanical-and-automation-engineering/

Time Structure Optimization of Logistics Chain during Assembly

Assembly operations as a basic unit crucially affect the productivity and overall efficiency of the entire production and assembly process. To increase the productivity of the entire production-assembly process is necessary to analyze the individual steps of assembly cycle, eventually find a solution that would be optimal and was used the gradual, concurrent or combined form of production-assembly process.

The first level creates a conceptual model implementing the assembly process. Indicates the principle of assembly solutions and determines the sequence of the production-assembly phases. It is therefore appropriate at this phase to create several structures (sub-assemblies) in order to clear the sequence and continuity of assembly steps. Assembly of guard portion is characterized by concurrent form of assembly process. Parts and assemblies going from department Pn to department Pn+1, and the total time of protector assembly cycle takes about 5.4 min/unit (one worker).

Website: http://www.arjonline.org/engineering/american-research-journal-of-mechanical-and-automation-engineering/

Modal Analysis of Axially Symmetric Structure

Currently, modal analysis as a tool for investigation of vibration becomes an important part of designer work. Whether it is necessary to perform determination of modal parameters, analyze amplitudes of vibration [1, 2], verify the numerical model experimentally [3, 4] or express the influence of different parameters on the vibration [5, 6], the knowledge of dynamic behavior of structures plays an important role as they are designed.

Website: http://www.arjonline.org/engineering/american-research-journal-of-mechanical-and-automation-engineering/

Effect of Dynamic Absorber Configuration on the Reduction of Vibration

The methodology how to design such a system is explained in the paper. The first type of dynamic absorber is composed by two masses connected to the seat by springs and dampers in parallel configuration. The second one is composed by two sprung masses connected to the seat in the series. The parameters of the seat suspension system and the dynamic absorber parameters were all determined by an optimization process based on genetic algorithms. The objective function for the optimization was to minimize the seats displacements. The vibration reduction of the seat is compared for both investigated cases.

Website:  http://www.arjonline.org/engineering/american-research-journal-of-mechanical-and-automation-engineering/

Acceptance and Re-verification Test of Length Metroscope

Paper deals with acceptance and re-verification of length measuring metroscope. The metroscope has been used very frequently for exercises in subject – Engineering Metrology at the bachelor study. New systematic errors have been obtained from calibration process. Other measurements have been also realized and corrections of results have been executed via using of new systematic errors. Measured errors from acceptance test have confirmed that metroscope is out of the limits defined through the maximum permissible error. Nevertheless the metroscope is fully functional and errors could be eliminated through the including of new measuring system consisting from suitable distance sensor.

Website:  http://www.arjonline.org/engineering/american-research-journal-of-mechanical-and-automation-engineering/

Comprehensive Approach to Technical Conditions of Electromechanical Units in Mechatronic Systems

Analysis of mechanical and electrical diagnostic parameters of electromechanical units is considered as an integrated approach. The relationship between mechanical, electric diagnostic parameters and technical conditions of the electric drive is investigated on the example of the stand consisting of the asynchronous motor, the coupling and a worm gear. The most sensitive diagnostic parameters were identified in case of various defects in electromechanical units. The change in the spectrum of vibration of the motor and the coefficients of the wavelet analysis of the electric current of the motor stator were investigated at idle and under load, in the absence and presence of the following defects: a decrease in the contact patch gear, misalignment coupling rims, as well as grazing rotor motor.

Website: http://www.arjonline.org/engineering/american-research-journal-of-mechanical-and-automation-engineering/