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Experiment E6/0,2 Lateral Passive Pressure – Rotation about the top
Koudelka, Petr ; Valach, Jaroslav ; Bryscejn, Jan
The paper gives information on a repeated long-term experiment E6/0,2 with lateral pressure at rest and passive pressure during wall rotation about the top towards into tested granular mass. The experiment was successfully finished in the last year 2011 and (together with a previous experiment E5/0,2) it should prove gained results which appear distinct from a theory of EUROCODE 7-1 contemporaneously used. Both experiments monitored and registered both pressure components and mass deformation and displacements into the sandy mas.
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Investigation of composite material degradation indicators using acoustic measurement: comparison with laser vibrometry
Fíla, Tomáš ; Urushadze, Shota ; Kytýř, Daniel ; Valach, Jaroslav ; Šperl, Martin
This paper deals with investigation of acoustic material degradation indicator (attenuation decrement drop of selected natural frequency) measured by a custom-built experimental device. Samples of C/PPS fibre composite material were analyzed. Acoustic signals were recorded and processed using spectral analysis and sound signal regression. Data measured by this method were verified by comparative experiment. Specimens were simultaneously measured using both acoustic experimental device and laser vibrometer. Modal analysis of the specimen were carried out prior to the experiment. This enabled assessment of specimens natural modes and therefore the best impact zone. In total, 10 measurements were performed for each specimen at the same level of degradation. Measured data were then processed and compared. The specimens were repetitively measured after designated number of loading cycles.
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Analýza chování dřeva v okolí zatlačovaného trnu při diagnostice konstrukčních prvků staveb
Kloiber, Michal ; Tippner, J. ; Hrivnák, J. ; Vichrová, Gábina ; Valach, Jaroslav
Technické řešení se týká diagnostického zařízení pro terénní i laboratorní měření konvenční pevnosti a modulu přetvářnosti při roztlačování čelistí ve vyvrtaném otvoru, spadá do oblasti testování kvality a vlastností materiálu, zejména dřeva. Zařízení podle technického řešení lze použít pro stanovení konvenční pevnosti a modulu přetvářnosti jakéhokoliv materiálu při roztlačení čelistí ve vyvrtaném otvoru ve zkoumaném objemu. Uplatnění najde dále v situacích, kde není možné či vhodné využít odporové vrtání a je potřeba určit mechanické vlastnosti dřeva po celém průřezu prvku. Výhodný je především pro svou rychlou a jednoduchou obsluhu bez nutnosti připojení do elektrické sítě.
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MONDIS: Knowledge-Based System of Failure of Historical Constructions
Valach, Jaroslav ; Cacciotti, Riccardo ; Čerňanský, Martin ; Kuneš, Petr
The main aim of introducing and developing a knowledge-based system of failure of historical constructions called MONDIS is to overcome a lack of data on defects of monuments. MONDIS proposes a methodology capable of reproducing the logical relationship between the manifestation of damage, its diagnosis and the possible interventions. Based on novel information sciences tools, like semantic technologies, the system will be able to assist users in finding similar failures cases, in analyzing the causes of damage and also suggesting suitable restoration techniques accordingly to conservation principles of intervention.
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Improved precision of stereometric measurement of relief's surface by means of structured light enhanced photometric stereo method
Valach, Jaroslav ; Bryscejn, Jan
Photometry is an interesting method for 3D measurement of surfaces with relief. It utilizes a relationship between depth of shadow determined intensity of light and surface normal orientation towards source of light. Advantage of methods incorporating this principle is their independence on distance between measured object and the measuring apparatus and scalable sensitivity suitable for relatively flat surfaces. On the other hand, there is a drawback as the photometric methods yield results up to an unknown multiplicative factor. One way how to overcome this limitation is to simultaneously describe the measured surface by means of another optical method. Among the -candidates-, the structured light projection is the most promising one for a simple implementation. The presentation of the possibility to integrate these two methods in unified system is main topic of this contribution.
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Operation Test of a New Experimental Technology for Research of Lateral Pressure
Koudelka, Petr ; Valach, Jaroslav ; Bryscejn, Jan
Hardware and software accessories of a original advanced experimental equipment was finished and debugged at the beginning of the last year. The equipment was constructed for a basic research of lateral pressure multi-phase granular materials and to verify a theoretically derived -General Lateral Pressure Theory- (GLPT). A number of technical tests of measuring components and computer controlling system were performed before the finish of the equipment development. Several quasi-experiments without a sample ended the equipment preparation at last. The first real experiment E5/0,2 with pressure at rest and passive pressure was used for an operation test of the new equipment. The paper deals the experimental technology (apparatuses, hardware, software, etc.) and experiences of them during an extremely slow movement of front wall. Also, it is mentioned a visual monitoring, 3D scan technology including.
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