2,027 research outputs found

    Energy conserving time integration scheme for geometrically exact beam

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    An energy conserving finite-element formulation for the dynamic analysis of geometrically non-linear beam-like structures undergoing large overall motions has been developed. The formulation uses classical displacement-based planar beam finite elements described in an inertial frame. It takes into account finite axial, bending and shear strains. A theoretically consistent approach is used to derive a novel and simple energy conserving scheme, using the unconventional incremental strain update rather than the standard strong form. Numerical examples demonstrate perfect energy and momenta conservation, stability and robustness of the scheme, and good convergence properties in terms of both the Newton-Raphson method and time step size. (c) 2006 Elsevier B.V. All rights reserved

    The strain-based beam finite elements in multibody dynamics

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    We present a strain-based finite-element formulation for the dynamic analysis of flexible elastic planar multibody systems, composed of planar beams. We consider finite displacements, rotations and strains. The discrete dynamic equations of motion are obtained by the collocation method. The strains are the basic interpolated variables, which makes the formulation different from other formulations. The further speciality of the formulation is the strong satisfaction of the cross-sectional constitutive conditions at collocation points. In order to avoid the nested integrations, a special algorithm for the numerical integration over the length of the finite element is proposed. The midpoint scheme is used for the time integration. The performance of the formulation is illustrated via numerical examples, including a stiff multibody system. (c) 2007 Elsevier Ltd. All rights reserved

    Tectonics Impact on Poljes and Minor Basins (Case Studies of Dinaric Karst)

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    Namen te študije je pokazati tektonske poteze v izbranih kraških poljih in manjših kotanjah Dinarskega krasa. Vrtine in gravimetrične meritve so ugotovile debele neogene nesprijete sedimente in apneniško dno pod gladino morja - kriptodepresije. Sedimenti so deli obsežne akumulacijske ravnine, ugreznjeni v kraška polja v spodnjem pliocenu. Seizmična aktivnost v sedanjosti nakazuje še trajajočo tektonsko aktivnost. Najgloblje (čez 100 m) in najmanjše kraško polje v slovenskem Dinarskem krasu, Globodol, je suho kraško polje v piezometrični vodni gladini. Pliokvartarno grezanje dna je edina možna razlaga za nastanek polja. Na Planinskem polju so znaki podtalne korozije in holocenskega tektonskega grezanja dna. Štiri kraška polja v Ravnih kotarih (Dalmacija) dokazujejo proces uravnavanja jezerskega dna pod plitvim pokrovom aluvialnih sedimentov. Izjemno globoke majhne kotanje so okoli 450 m globoko Rdeče jezero (Hercegovina) in kotanji pri Črnomlju in Kočevju (Slovenija), okoli 300 m oziroma 100 m pod gladino morja.  The aim of this study is to show tectonic features in selected poljes and minor basins in the Dinaric Karst. Boreholes and gravimetric measurements show thick Neogene loose sediments and the rocky bottom below the sea level - real cryptodepressions. The sediments make parts of a large plain that subsided at the end of the low Pliocene. The recent seismic activity in this area proves the ongoing tectonic process. The deepest (more than 100 m) and the smallest polje in the Slovenian Dinaric karst, Globodol is a dry polje in the piezometric level. Quaternary subsidence of the bottom is the only reasonable explanation of its genesis. On Planinsko polje there are signs ob suballuvial corrosion and the indicators of the Holocene tectonic subsidence. Four poljes in the Ravni kotari (Dalmatia) are shallow basins in the first stage of development. They prove the process of the bottom levelling below the shallow cover of alluvial sediments. An extremely deep small basin is about 450 m deep Red Lake (Hercegovina) and small basins at Črnomelj and Kočevje (Slovenia), 300 m and 100 m deep below the sea level.

    The 100th birth anniversary of Professor Svetozar Ilešič (1907-1985)

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    Geomorphology of the Pohorje mountains

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    The Pohorje mountain range, young mountains with prevailing metamorphic rocks and dacite, continues to uplift above the igneous laccolith in the area of the rapid rising asthenosphere in the transition to the Pannonian basin also due to changes in temperature and, resultantly, of the density of uplifting dacite- and other intrusions which have not metamorphosed the surrounding sediments. On the Pohorje by the river Drava (hereinafter the Drava Pohorje), the drainage network does not match the orography, because, between the Vuzenica-Radlje basin and Fala, the Drava epigenetically deepened its gorge into the marginal range of Kobansko. Modest plateaus on the ridge of the Pohorje originate from the time when the base level maintained a cover of the so-called Eibiswald strata between the Karavanke and the Kobansko in the upper Miocene. The originally larger ridge plateau in the centre of the Pohorje was lowered by erosion and periglacial processes; it has been preserved as an inclined plateau on the Eastern Pohorje. Explained through the recent tectonic shifting, established by means of GPS in the years 1996–2002 at the peak Velika Kopa, is the southeastwards curving of the five valleys above the Legen terrace where, supposedly, original headwaters of the Spodnja Mislinja came from. Due to its geological, geomorphological and hydrological peculiarities the Legen Quaternary terrace deserves that it should be declaired the ‘geopark’, the first one in Slovenia. Even more explicit and extensive is the westwards curving of the valleys on the northern slope of the Pohorje, and their northeastward orientation in the Ribnica-Lovrenc-Selnica valley system. In the east section of the Lovrenc valley system above Fala the brook Rečnikov potok has not adjusted its course to the recent tectonic subsiding, so that its valleys run obliquely to the slope inclination. The up to 700 metres deep Mislinja rift lowered the central ridge of the Pohorje to 1299 metres. Blowing intensely across it, the northeastern Pleistocene cold winds made possible the origination of two smaller glaciers in the upper drainage basin of the Radoljna. The gently sloping Pohorje landforms are not the result of the old age but of the disintegration of granular rocks to permeable sand, above which the thick cover of continuous roots of grasses and prevailing spruce reduces the erosion

    Family Functioning and Secondary Traumatic Stress in Military Families: A Qualitative Study

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    The purpose of this study was to explore secondary traumatic stress and family functioning in military families. Six licensed mental health professionals, including social workers and a marriage and family therapist with experience working directly with military families participated in this study. Using a qualitative design, participants were interviewed regarding their experience working with these families. Five themes emerged from the data including: (1) strength of communication within the family can impact functioning; (2) the non-veteran parent often takes on various aspect in the role of both parents; (3) children often present secondary traumatic stress symptoms outside of the home; (4) family functioning and responses to trauma are unique to each family; and, (5) family and couples counseling is an essential treatment tool for these families. Limitations were lack of discussion surrounding female veteran to male spouses, as well as same sex partnerships. This study presents information through the personal and professional lens of the participants and draws awareness to PTSD and secondary traumatic stress in military families

    Family Functioning and Secondary Traumatic Stress in Military Families: A Qualitative Study

    Get PDF
    The purpose of this study was to explore secondary traumatic stress and family functioning in military families. Six licensed mental health professionals, including social workers and a marriage and family therapist with experience working directly with military families participated in this study. Using a qualitative design, participants were interviewed regarding their experience working with these families. Five themes emerged from the data including: (1) strength of communication within the family can impact functioning; (2) the non-veteran parent often takes on various aspect in the role of both parents; (3) children often present secondary traumatic stress symptoms outside of the home; (4) family functioning and responses to trauma are unique to each family; and, (5) family and couples counseling is an essential treatment tool for these families. Limitations were lack of discussion surrounding female veteran to male spouses, as well as same sex partnerships. This study presents information through the personal and professional lens of the participants and draws awareness to PTSD and secondary traumatic stress in military families
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