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Stacionární drtič železobetonových panelů - analýza dynamických účinků do základů stroje / Stationary crusher concrete panels - analysis of dynamic effects in the machine foundationsMacejka, Andrej January 2019 (has links)
This diploma thesis is concerned with design and proposal of parameters of drop hammer Davon for crushing of steel reinforced concrete panels with weight of the ram 5 t. The main topic is an emergency condition when there is no crushed material between ram and anvil. The design is established by simulation of an impact by finite element analysis with respect to required ground bearing capacity.
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Análise vibratória de fundações de máquinas sobre estacas. / Vibration Analysis of machine foundation on piles.Guilherme Alan Souza Costa 27 September 2013 (has links)
Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / A análise de fundações sob solicitações dinâmicas é algo sempre presente
em projetos na área industrial. É um campo pouco explorado na área de engenharia
geotécnica, onde existem relativamente poucas informações no Brasil, de maneira
geral. O método mais comum de realizar essas análises é a simplificação de
modelos estruturais a partir do uso de molas. Sabe-se que esses coeficientes de
reação têm uma variação relativamente grande e que esse enfoque de projeto pode,
em alguns casos, mostrar-se contra a segurança ou levar a superdimensionamentos
desnecessários. Verifica-se, então, a necessidade de uma avaliação mais criteriosa,
utilizando a interação solo x estrutura, onde as molas comumente utilizadas nas
análises vibratórias convencionais são substituídas pela rigidez real do solo quando
concebido como um meio contínuo, através de sua discretização pelo método dos
elementos finitos. A presente dissertação analisa o problema através do módulo de
dinâmica do programa Plaxis 2D. Neste tipo de análise, além da modelagem do solo
como um meio contínuo, torna-se possível introduzir condições de contorno
específicas ao problema em estudo, múltiplas camadas de solo, sejam horizontais
ou inclinadas, além da introdução de amortecedores capazes de evitar a reflexão
espúria das ondas incidentes nos limites da malha de elementos finitos e assim
modelar mais adequadamente a perda de energia por radiação. A presente
dissertação compara medições experimentais e soluções eficientes de métodos
vibratórios clássicos com a resposta obtida pelo MEF, mostrando resultados
bastante satisfatórios tanto pelos métodos clássicos quanto pelo MEF. / The foundation analysis by dynamic solicitations is always present in industrial
projects. It is an area which is poorly explored in geotechnical engineering and there
are few information about this subject in Brazil, in general. The most common method
to realize this analysis consists in simplifies structural models by using springs. It is
known that these reaction coefficients have a large range of variation and this
projects focus can, in some cases, be against the safety side or lead to unnecessary
over designs. This proves the necessity to do a more criterious evaluation by using
the interaction soil x structure where the springs usually used in common vibration
analysis are replaced by the real stiffness of soil when designed as a continuous
medium through its discretization by finite element method. This present dissertation
analyzes the problem through the dynamic modulus of the software PLAXIS 2D. In
this sort of analysis, besides the modeling of soil as a continuous medium, it
becomes possible to introduce specific boundary conditions associated to the studied
problem, multiple soil layer, that can be horizontals or inclined, in addition to the
introduction of dampers able to avoid the spurious reflection of incident waves on the
boundary of finite element mesh and then to model more efficiently the energy loss
by radiation. This present dissertation compares experimental measurements and
efficient solutions of classical vibration methods with the response obtained by FEM,
showing results quite satisfactory both by classical methods and by FEM.
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Análise vibratória de fundações de máquinas sobre estacas. / Vibration Analysis of machine foundation on piles.Guilherme Alan Souza Costa 27 September 2013 (has links)
Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / A análise de fundações sob solicitações dinâmicas é algo sempre presente
em projetos na área industrial. É um campo pouco explorado na área de engenharia
geotécnica, onde existem relativamente poucas informações no Brasil, de maneira
geral. O método mais comum de realizar essas análises é a simplificação de
modelos estruturais a partir do uso de molas. Sabe-se que esses coeficientes de
reação têm uma variação relativamente grande e que esse enfoque de projeto pode,
em alguns casos, mostrar-se contra a segurança ou levar a superdimensionamentos
desnecessários. Verifica-se, então, a necessidade de uma avaliação mais criteriosa,
utilizando a interação solo x estrutura, onde as molas comumente utilizadas nas
análises vibratórias convencionais são substituídas pela rigidez real do solo quando
concebido como um meio contínuo, através de sua discretização pelo método dos
elementos finitos. A presente dissertação analisa o problema através do módulo de
dinâmica do programa Plaxis 2D. Neste tipo de análise, além da modelagem do solo
como um meio contínuo, torna-se possível introduzir condições de contorno
específicas ao problema em estudo, múltiplas camadas de solo, sejam horizontais
ou inclinadas, além da introdução de amortecedores capazes de evitar a reflexão
espúria das ondas incidentes nos limites da malha de elementos finitos e assim
modelar mais adequadamente a perda de energia por radiação. A presente
dissertação compara medições experimentais e soluções eficientes de métodos
vibratórios clássicos com a resposta obtida pelo MEF, mostrando resultados
bastante satisfatórios tanto pelos métodos clássicos quanto pelo MEF. / The foundation analysis by dynamic solicitations is always present in industrial
projects. It is an area which is poorly explored in geotechnical engineering and there
are few information about this subject in Brazil, in general. The most common method
to realize this analysis consists in simplifies structural models by using springs. It is
known that these reaction coefficients have a large range of variation and this
projects focus can, in some cases, be against the safety side or lead to unnecessary
over designs. This proves the necessity to do a more criterious evaluation by using
the interaction soil x structure where the springs usually used in common vibration
analysis are replaced by the real stiffness of soil when designed as a continuous
medium through its discretization by finite element method. This present dissertation
analyzes the problem through the dynamic modulus of the software PLAXIS 2D. In
this sort of analysis, besides the modeling of soil as a continuous medium, it
becomes possible to introduce specific boundary conditions associated to the studied
problem, multiple soil layer, that can be horizontals or inclined, in addition to the
introduction of dampers able to avoid the spurious reflection of incident waves on the
boundary of finite element mesh and then to model more efficiently the energy loss
by radiation. This present dissertation compares experimental measurements and
efficient solutions of classical vibration methods with the response obtained by FEM,
showing results quite satisfactory both by classical methods and by FEM.
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Prodejní a servisní centrum Praha – stavebně technologický projekt / Sales and service center Prague - the building technological projectTrhlík, Lukáš January 2012 (has links)
In this diploma thesis deals with execution of ground works, foundation constructions, steel and armored concrete monolithic framework of the sales and service center in Prague. Establishment of the building will be done on armored concrete basement feet, strips and basement plate. The building is desinged in part as a steel framework and in part as a armored concrete framework. The building technological project contains for the phases primarily time and financial plan of object, technology prescription, time schedule, budget, model of the building site accessories, model of the machines, check and test plan, safety plan.
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Linear FEM Analysis of a Commercial Elastomer for Machine FoundationsJakel, Roland 20 June 2024 (has links)
The presentation describes partial results from an industrial project in which a transmission
test bench from ZF Prüfsysteme was decoupled from the foundation in terms of vibration using
commercial PU foam material ('Sylomer' SR220 from Getzner).
The presentation shows how this material was extensively tested by the manufacturer and
characterized in numerous data sheets in order to enable the engineer to perform a simple,
operating point-dependent dynamic design using clear diagrams and the classic equation for a
single-mass oscillator.
However, if a more complex analysis is to be carried out using the finite element method, e.g. to
determine all 6 rigid body shapes and natural frequencies of the dynamically decoupled test rig and
not just the purely vertical natural shape/frequency, the apparent elasticity and shear moduli
specified in the manufacturer's data sheets must be converted into true values for the
corresponding operating points, which can then be used in a linear FE calculation.
For this purpose, FEM models of the elastomer test specimens are generated for different shape
factors. The conversion of the apparent to the true characteristic values is then carried out using
the optimizer available in the PTC software “Creo Simulate” in a so-called 'feasibility study' and
the results are discussed.
It can be seen that the true moduli of elasticity and transverse strain coefficients are only slightly or
no longer dependent on the form factor. Depending on the density of the PU foam, the transverse
strain coefficient is also significantly lower than 0.5. The true shear modulus is practically identical
to the measured shear modulus, as a pure biaxial stress and strain state occurs in the shear
specimens, in which strain restraints due to transverse strain plays no role - quite unlike in the
specimens loaded in the normal (compression) direction, in which triaxial compression stress
states occur due to transverse strain restraints.
Finally, the true material properties determined in this way are used for an exemplary modal
analysis of the entire, idealized test rig on the strip foundation using the finite element method. The
error is evaluated if the apparent modulus of elasticity and a Poisson ratio of zero is used instead,
so that a simple evaluation and error estimation of analysis results is possible in practical
applications. / Der Vortrag beschreibt Teilergebnisse aus einem industriellen Projekt, in dem ein
Getriebeprüfstand der ZF Prüfsysteme schwingungstechnisch über kommerzielles PU-
Schaummaterial („Sylomer“ SR220 der Firma Getzner) vom Fundament abgekoppelt wurde.
Der Vortrag stellt dar, wie dieser Werkstoff vom Hersteller umfangreich getestet und in zahlreichen
Datenblättern charakterisiert wurde, um dem Ingenieur schließlich eine einfache,
betriebspunktabhängige dynamische Auslegung mittels übersichtlicher Diagramme und der
klassischen Gleichung für einen Einmassenschwinger zu ermöglichen.
Soll jedoch eine aufwendigere Analyse mittels der Methode der Finiten Elemente durchgeführt
werden, z.B. um alle 6 Starrkörperformen und Eigenfrequenzen des dynamisch abgekoppelten
Prüfstandes zu bestimmen und nicht nur die rein vertikale Eigenform/Eigenfrequenz, müssen die in
den Herstellerdatenblättern angegeben formzahlabhängigen scheinbaren Elastizitäts- und
Schubmoduli in wahre Werte für die entsprechenden Betriebspunkte umgerechnet werden, die
dann in einer linearen FE-Rechnung verwendet werden können.
Dafür werden FEM-Modelle der Elastomer-Probekörper für verschiedene Formfaktoren erzeugt.
Die Umrechnung der scheinbaren in die wahren Kennwerte wird anschließend mittels des in der
PTC-Software „Creo Simulate“ vorhandenen Optimierers in einer sogenannten
„Machbarkeitsstudie“ durchgeführt und die Ergebnisse diskutiert.
Es zeigt sich, dass die wahren E-Moduli und Querdehnzahlen nur noch gering bzw. nicht mehr
vom Formfaktor abhängen. Je nach Dichte des PU-Schaums stellt sich auch eine Querdehnzahl
von deutlich kleiner als 0,5 ein. Der wahre Schubmodul ist praktisch identisch wie der gemessene
Schubmodul, da in den Schubproben ein reiner zweiachsiger Spannungs- und Dehnungszustand
auftritt, in dem Dehnungsbehinderung durch Querdehnung keine Rolle spielt – ganz anders als in
den in Normalenrichtung (Druck-) belasteten Proben, in denen durch die Querdehnungs-
behinderung dreiachsige Spannungszustände auftreten.
Schließlich werden die so bestimmten wahren Werkstoffkennwerte für eine exemplarische
Modalanalyse des gesamten, idealisierten Prüfstandes auf den Streifenfundamenten mittels der
Methode der Finiten Elemente verwendet. Der Fehler wird bewertet, wenn man stattdessen den
scheinbaren E-Modul und eine Querdehnzahl von Null verwendet, so dass in der
Anwendungspraxis eine einfache Bewertung und Fehlerabschätzung von Analyseergebnissen
möglich ist.
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