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1
Content available Zmechanizowane obudowy ścianowe w warunkach zagrożenia wstrząsami górotworu w GZW – stan obecny w ujęciu statystycznym
Świątek Janina
Mining – Informatics, Automation and Electrical Engineering
|
2019
|
R. 57, nr 2
21--32
PL
Górnośląskie Zagłębie Węglowe (GZW) prowadzi eksploatację pokładów węgla głównie w warunkach zagrożenia wstrząsami górotworu. Właściwy dobór obudowy do wymienionych warunków jest istotnym czynnikiem bezpiecznej i efektywnej eksploatacji. W publikacji opartej na analizach własnych przeprowadzonych na grupie danych zebranych na podstawie prac zrealizowanych przez Zakład Technologii Eksploatacji, Tąpań i Obudów Górniczych, Głównego Instytutu Górnictwa, przy wykorzystaniu statystyki opisowej, przedstawiono: stopień zagrożenia wstrząsami górotworu, stosowane konstrukcje obudów zmechanizowanych w warunkach zagrożenia wstrząsami górotworu oraz sposób oceny ich podporności na przeciążenia dynamiczne.
2
Content available Powered roof support in conditions of mining tremors in Upper Silesian Coal Basin – current state in terms of statistical analysis
Świątek Janina
Mining – Informatics, Automation and Electrical Engineering
|
2019
|
R. 57, nr 2
21--26
EN
Coal mining in Upper Silesian Coal Basin (USCB) is conducted in the conditions of frequent mining tremors. The longwall roof support significantly impacts the safety and efficacy of the mining process. The paper presents the assessment of mining tremor hazard, the procedure of designing powered roof supports used in the conditions of tremors, and a method of evaluating supports’ resistance to dynamic overloads. The research was based on analyses carried out by the authors on the data collected during the works carried out by the Department of Extraction Technologies, Rockbursts, and Mining Support. The data was analysed using descriptive statistics.
3
Content available Numerical analysis of the risk of neck injuries caused by IED explosion under the vehicle in military environments
Mackiewicz A., Będziński R., Sławiński G., Niezgoda T.
Acta Mechanica et Automatica
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2016
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Vol. 10, no. 4
258--264
EN
As a result of an explosion under a military vehicle, the risk of threat to life and health of the crew increases. Examination of this event in terms of the security of soldiers comes down to a complex analysis of the mutual interaction of the body of a soldier, seating and structural elements of the vehicle. As a result, shock wave impacts can cause tremor resulting from the construction of the vehicle and acceleration of the passenger's body. This study attempts to analyze the impact of an explosion of an improvised explosive device (IED) under the military vehicle with the risk of cervical spine injuries of soldiers. The analysis was carried out using numerical methods in the LS-DYNA program and was carried out taking into account the variable displacement values and acceleration recorded during the\ explosion. The study used a model of the body of a soldier in the form of a Hybrid III 50th Male Dummy.
4
Content available remote Dynamic loads in some movement structures in acrobatics. A preliminary study
Dworak L. B., Twardowska M., Wojtkowiak T., Kmiecik K., Mączyński J.
Acta of Bioengineering and Biomechanics
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2005
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Vol. 7, nr 1
69-75
EN
The aim of the paper was identification of force-time characteristics of ground reaction forces exerted during take-off and landing phases in the six typical acrobatic elements. The tests of a pilot study character were carried out on two professional athletes aged 17 and I8. The levels of such parameters characterizing dynamic loads and overloads of examined movement structures as: maximal and average values of vertical ground reaction forces, total time of support phases, time necessary for generation of maximal force, force buildup indexes as well as force impulses were calculated. The results obtained suggest that dynamic overloads are serious and of traumatic character.
5
Content available remote A study characterizing dynamic overloads of professional dancers. Biomechanical approach
Dworak L. B., Gorwa J., Kmiecik K., Mączyński J.
Acta of Bioengineering and Biomechanics
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2005
|
Vol. 7, nr 1
77-84
EN
Many jumps made in classical and modem ballet are responsible for serious injuries. A pilot experiment that was earned out with two professional dancers measured the temporary character of ground reaction forces in a few chosen elements of classical dance. The method of piezoelectric dynamometry as well as video recording were applied. The results of the experiment concerning the dynamic overloads, which are defined by the value of ground reaction forces, allow us to set the direction of a further research in the area of biomechanical interpretations.
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