Diploma thesis deals with securing of foundation pit of family house in given geological conditions situated in Brno-Kohoutovice. The aim of the thesis is to list possible solutions of securing foundation pits in general and solve this geotechnical problem with an appropriate solution. Static calculations were performed by geotechnical software GEO5.

Diploma thesis deals with securing of foundation pit of family house in given geological conditions situated in Brno-Kohoutovice. The aim of the thesis is to list possible solutions of securing foundation pits in general and solve this geotechnical problem with an appropriate solution. Static calculations were performed by geotechnical software GEO5.

The aim of this work is a static analysis of the reinforced concrete frame structure loaded by the effects of seismic loading. The work deals with the solution of multi-storey reinforced concrete structure designed for common loading conditions and further for possibilities of strengthening of the structure on effect of seismic loading. In the first phase of the work, the static analysis and the design of the main load-bearing elements of the frame structure (columns and main girder) were carried out for the ultimate limit state for the standard design load. In the second phase, the static analysis of the structure for the effects of accidental actions from low and high seismicity was performed and it was assessed whether the main load-bearing elements of the structure would continue to comply. Given that the structure did not satisfy the accidental actions of seismic loading, various ways of structure strengthening were designed and analyzed for their impact on the global and local behaviour of the structure. Also the designing of additional steps for structural reliability were performed. Static analyzes were performed in Scia Engineering and RFEM Dlubal software.

Fragestellung: Auf dem Gebiet der Bandverletzungen des Kniegelenks stellt die Knieluxation das schwerste Krankheitsbild dar. Die Verletzung ist selten, es existiert bisher kein evidenzbasiertes einheitliches Therapieschema und in der Literatur werden verschiedene Behandlungskonzepte diskutiert. Die operative Therapie von Kniegelenksluxationen zeigt gegenüber konservativen Behandlungsansätzen bessere Ergebnisse. Ein operativer Eingriff im Sinne einer anatomischen Rekonstruktion sollte in den ersten drei posttraumatischen Wochen (akute Phase) erfolgen. Seit dem Jahr 2014 stellt das „Ligament bracing“ ein neues Konzept zur Therapie der akuten hochgradigen Knieluxation dar. Es zielt auf die einzeitige Wiederherstellung der biomechanisch-dynamischen Funktionalität der Kreuzbänder. Das Ziel der vorliegenden Studie war der Vergleich der klassischen Ligament bracing Technik (komplettes Bracing [komplBr]: Nahtaugmentation + Bracing des hinteren [HKB] und vorderen Kreuzbandes [VKB]) mit einer reduzierten Technik (partielles Bracing [partBr]: nur Bracing des HKB). Weiterhin wurden epidemiologische Parameter, Begleitverletzungen und diagnostische Vorgehensweisen erfasst. Material und Methode: An zwei Kliniken einer Stadt (Gruppen komplBr und partBr) wurden in einem 24- Monatszeitraum 18 Patienten nach hochgradigen Kniegelenksluxationen (Typen III und IV der Schenck-Klassifikation) operativ versorgt. 16 dieser Patienten wurden in eine prospektive Beobachtungsstudie eingeschlossen. Als Ausschlusskriterien wurden Luxationsfrakturen und Voroperationen (Kreuzbandersatzplastiken) an den jeweiligen Kniegelenken definiert. In Gruppe komplBr (n=9, Alter 16-72 Jahre) wurden alle Patienten nach klassischer Ligament bracing Technik operiert: transossäre Ausziehnähte der Kreuzbänder in Kombination mit Fadenaugmentationen („Bracing“) des VKB und HKB. In Gruppe partBr (n=7, Alter 23-48 Jahre) erfolgte ein isoliertes Bracing des HKB. In beiden Gruppen erfolgte die Naht oder Rekonstruktion der Seitenbänder in Abhängigkeit des Schweregrades. Die Patienten wurden prospektiv über 12 Monate klinisch und radiologisch nachuntersucht. Neben einer ausführli- chen Dokumentation des Verletzungsausmaßes, sowie diagnostischer und therapeutischer Vorgehensweisen und Revisionsoperationen, erfolgte ein Jahr postoperativ eine klinische Untersuchung entsprechend des Formblattes IKDC 2000 (Bewertung anhand von 4 Graden; A: normal, B: fast normal, C: abnormal, D: deutlich abnomal). Weiterhin wurden zur funktionellen subjektiven Bewertung der Lysholm-Score (0 - 100 Punkte), der Tegner-Score (0 - 10 Punkte) und der kniespezifische Fragebogen nach IKDC (0 - 100 Punkte) erhoben. Im Rahmen der radiologischen Nachuntersuchung (ebenfalls ein Jahr postoperativ) wurden Standartprojektionen und gehaltene Aufnahmen (anteriore und posteriore Translation im Seitenvergleich mittels Telos-Gerät) angefertigt. Ergebnisse: Statistisch signifikante Unterschiede zwischen den Gruppen komplBr und partBr (p<0,05) ergaben sich im Tegner-Score bzgl. des geringeren Aktivitätsverlustes zugunsten der Gruppe komplBr. Daneben zeigt die Bewertung des passiven Bewegungsdefizites im Formblatt IKDC 2000 signifikante Unterschiede zugunsten der Gruppe partBr. Die Absolutwerte der gemessenen Beuge- und Streckdefizite zeigen jedoch keine signifikanten Unterschiede. Die weiteren Ergebnisse weisen keine statistisch signifikanten Unterschiede auf. Die Abschlussbewertung des klinischen Formblattes IKDC 2000 ergab nach 12 Monaten im Mittel den Grad C (Gruppe komplBr: 3xB, 5xC; Gruppe partBr: 5xC, 2xD). Der Lysholm-Score lag zum Zeitpunkt der Nachuntersuchung für das Gesamtkollektiv bei 78,3 (59-95) Punkten (83 Gruppe komplBr, 73 Gruppe partBr). Der Tegner-Score zeigte bei Gruppe komplBr vor dem Unfall im Mittel 5,3 (4-7) Punkte und bei Gruppe partBr 6,7 (6-7) Punkte. Im Rahmen der Nachuntersuchung erreichte er 4,0 (3-5) Punkte bzw. 4,3 (4-5) Punkte. Der mittlere subjektive IKDC-Score betrug nach einem Jahr im Median 65 (43-87) Punkte (Gruppe komplBr: 73, Gruppe partBr: 56). Im Seitenvergleich zeigte sich in den gehaltenen Röntgenaufnahmen eine vermehrte mittlere anteriore Translation von 0,8 (0-2) mm (Gruppe komplBr) bzw. 2 (0-6,2) mm (Gruppe partBr) und eine vermehrte dorsale tibiale Translation von 3,7 (1-7) mm (Gruppe komplBr) bzw. 4,8 (0,8-8) mm (Gruppe partBr). Zwei Patienten boten eine Rezidivinsuffizienz des VKB (Gruppe komplBr: 0, Gruppe partBr: 2). 73 % aller Patienten (komplBr: 63%, partBr: 86%) unterlagen binnen eines Jahres einer Sekundärintervention aufgrund von Arthrofibrose. Alle Patienten gingen zum Zeitpunkt der Einjahresuntersuchung ihrem alten Beruf nach. Schlussfolgerungen: Das Therapiekonzept des Ligament bracing führt sowohl in der „kompletten“ als auch in der „partiellen“ Methode – gemessen am Schweregrad der Verletzung - zu überwiegend guten Behandlungserfolgen mit tendenziell höheren Werten für das kombinierte VKB/HKB Bracing. Partielles Bracing führt zu einem signifikant höheren Aktivitätsverlust (Tegner-Score). Zudem zeigt es eine tendenziell höhere Rate von Insuffizienzen des VKB. Bezogen auf die erreichte HKB-Stabilität weisen beide Methoden sowohl stabile, als auch instabile Ergebnisse auf. Die geringe Inzidenz des Krankheitsbildes erfordert zur Aufdeckung weiterer Unterschiede multizentrische Studien, um höhere Fallzahlen miteinander vergleichen zu können. Aufgrund der hohen Arthrofibroserate sind beide durchgeführten Methoden in der Mehrzahl der Fälle mit einem zweiten operativen Eingriff in Narkose verbunden gewesen. Dieser Erkenntnisgewinn spielt in der Patientenaufklärung für das Konzept Ligament bracing eine wichtige Rolle. Die Ergebnisse dieser Arbeit legen zudem eine Überprüfung der angewendeten Nachbehandlungskonzepte nahe.

Ankle sprains are among the most common injuries for participants in running and jumping sports. Following an initial sprain injury, many (30-40%) will develop chronic ankle instability (CAI), characterized by a perception of instability and repeated sprain injuries. Quasi-static test methods indicate poor postural stability and joint position sense (JPS) as associated motor control deficits. Little research, though, has investigated ankle motor control under dynamic (simulated sport) or fatigue conditions. To better understand factors contributing to the increased sprain rate in adults with CAI, three studies were completed investigating the roles of running speed, fatigue, and ankle bracing on motor control in adults with CAI. First, two groups with and without ankle instability performed dynamic athletic maneuvers at each of two running speeds. Joint kinematics and kinetics were measured to identify differences in motor control strategies. Participants also completed two quasi-static tests (JPS and single leg drop landings). The level of correspondence between quasi-static and dynamic test methods was of particular interest. A second study compared fatigue development and fatigue adaptations when executing single leg drop landings. Strength loss and ratings of perceived exertion measured fatigue development, and joint kinematics, kinetics, and muscle activation quantified drop landing performance. A final study examined whether ankle braces, a common treatment for ankle sprains, retained their effectiveness when an athlete was fatigued. JPS and ankle stiffness were measured before and after a fatigue protocol while using each of three brace conditions. Overall, results indicated that adults with CAI exhibit distinct adaptations to changes in speed and to fatigue that may increase their risk for ankle reinjury. Specific changes, however, depended on the particular activity being performed. Single leg drop landing kinematics may be a good representation of kinematics during dynamic athletic performance. Neither test brace improved JPS following fatigue, but each may be effective in providing mechanical stiffness compared to an unbraced condition. The effectiveness of a particular test brace, however, may be gender-specific. Future work should focus on identifying the benefits of different braces under broader conditions to help inform brace selection. / Ph. D.

Falls continue to be a major problem in the residential construction industry and account for a large number of injuries and fatalities each year (US Department of Labor, 2012).  The effects of a fall are catastrophic to the workers and their families as well as the construction company and surrounding community.  Prevention of these incidents has been the primary focus of organizations such as the Occupational Safety and Health Administration (OSHA).  To reduce the number of falls on residential construction sites, OSHA has put forth several standards that require the use of fall protection.  Although guidelines have been provided, there have been concerns and complaints regarding the standards as well as methods and materials that should be used. The goal of this research was to measure the behavior of a five truss roof system with various anchor points and bracing configurations loaded by a horizontal force.  A lab built roof system was used to test three different anchor types with three forms of temporary bracing.  The materials and methodology used in this testing were based on common materials and practices currently used in the residential construction industry. The results of this research show that anchors must engage multiple trusses to spread the applied load throughout the roof system.  Several forms of temporary bracing such as lateral, diagonal, and sway bracing, are also required to strengthen the roof system allowing it to withstand an applied load. / Master of Science

An ultra-lightweight buckling-restrained brace (ULWBRB) is developed using a highly ductile aluminum core and FRP restrainer. Utilization of lightweight materials results in a BRB that is 25% the weight of traditional mortar-filled tube varieties allowing easy installation in small to medium sized buildings requiring seismic retrofit without the need for heavy equipment. Construction utilizes commonly stocked materials able to be customized for required strength, drift, and geometry limitations. Analytical single degree of freedom (SDOF) and Euler buckling models are compared with published equations to determine the required restrainer stiffness (RRS). SDOF models yield RRS values 200% higher than the Euler model. Applied end moments due to frame deformation are incorporated into a modified design method that gives RRS values 50% higher than Euler model without eccentricity. RRS is provided using a bundled and wrapped FRP tube configuration using a developed shear flow method considering composite action. Uniaxial low-cycle fatigue (LCF) testing of a 6061-T6 candidate alloy provides data for a constitutive model using combined kinematic-isotropic hardening. LCF testing of round short gage coupons indicates the candidate alloy is capable of stable cycling to 2%, 3%, and 4% total strain with excellent ductility. Early fracture of specimens at 24, 18, and 11 cycles, respectively, also indicates that other candidate alloys should be examined for improved fatigue life. However, inconsistency is noted between similar tests of 6061-T6 that were able to achieve up to 76 cycles at 2.5% total strain. ULWBRB FEA models loaded monotonically consistently give higher RRS values as compared to the analytical methods. This is due to assignment of initial imperfections, longer more realistic unbraced length, higher axial loads achieved through the post-yield region, and plastic hinging potential. Cyclic simulations of braces with the same RRS values are also able to achieve reliable and stable hysteretic behavior through 21 cycles. If a less stiff restrainer is used, cumulative energy dissipation potential is reduced considerably due to pinched hysteresis loops and strain ratcheting. Applied end moments are found to have a linear effect on the RRS that can be modeled by superposition of the buckling effect plus end moment.

No description available.

The increased prevalence of crash avoidance technologies like autonomous emergency braking necessitates understanding of occupant responses during low-speed frontal pre-crash braking and low-severity crash events. Active human body models (HBMs) have emerged as valuable tools to evaluate occupant safety during these events, but must be validated with relevant volunteer data to accurately represent the responses of live occupants. The objective of this dissertation was to quantify the occupant responses of relaxed and braced 5th percentile female and 50th percentile male volunteers during low-speed frontal and frontal-oblique sled tests designed to simulate pre-crash braking and low-severity crash events. A study comprised of 160 low-speed sled tests was performed with 20 volunteers. The volunteers' kinematics, kinetics, and muscle responses were compared to determine how altering impact direction (frontal and frontal-oblique), impact severity (1 g and 2.5 g), demographic group (mid-size male and small female), and muscle state (relaxed and braced) affected occupant responses. The volunteers' occupant responses were significantly affected by impact direction, impact severity, demographic group, and muscle state. The frontal-oblique tests resulted in greater leftward excursions compared to the frontal tests. Increasing the pulse severity resulted in greater forward excursions, reaction forces, and muscle activation. The male volunteers exhibited greater forward excursions and reaction forces compared to the female volunteers. However, the two demographic groups exhibited similar muscle activation during the sled tests. Bracing increased the volunteers' initial joint angles, muscle activation, and reaction forces prior to the sled tests. Bracing decreased forward excursions and increased reaction forces during the sled tests. The relaxed volunteers exhibited greater relative changes in occupant responses compared to the braced volunteers. Overall, this study demonstrated that muscle activation significantly affected the volunteers' kinematics, kinetics, and muscle responses for both mid-size males and small females during low-speed events. Observed differences between demographic groups were more prominent when relaxed and more diminished when braced. These results underscore the importance of validating active HBMs with relevant volunteer data in order to be more representative of live occupants for a wider range of demographic groups in varying muscle states. Finally, this dissertation provides a large, comprehensive, and novel biomechanical dataset that can be used to develop and validate active HBMs for use in assessing occupant response during frontal pre-crash braking and low-severity crash events. These models will help improve the understanding of potential injury risk and development of effective vehicle safety systems for use during low-speed events. / Doctor of Philosophy / Computer models, known as active human body models (HBMs), have emerged as tools that can be used to assess occupant safety during low-speed vehicle crashes. In these types of events, occupants have enough time to react and potentially brace before the crash, which could in turn affect their responses during the crash. It is important to understand how occupants respond during crashes so that effective vehicle safety systems can be developed. Active HBMs are particularly valuable because they can simulate muscle activation to reflect the response of live occupants. However, data are needed from live occupants to ensure that these models are accurate. To gather this data, a study was performed where volunteers experienced low-speed frontal sled tests when they were relaxed and braced. The sled tests were designed to simulate pre-crash braking and low-severity vehicle crashes. Mid-size male and small female volunteers were recruited to participate to represent the standard adult occupant populations used in current frontal impact vehicle safety standards. A motion capture system was used to measure the volunteers' forward motion, load cells were used to measure the volunteers' exerted reaction forces on the test buck, and electrodes were used to measure the volunteers' muscle activity. The volunteers' responses were significantly different between the relaxed and braced muscle states, and between the males and females. Comparing between males and females, the males moved farther forward and exerted larger reaction forces, but both demographic groups exhibited similar muscle responses. Comparing between muscle states, bracing increased the volunteers' muscle activation and reaction forces before the sled tests. Bracing also increased the volunteers' reaction forces during the sled tests, but decreased forward movement. Overall, the volunteers exhibited greater relative changes in response when they were relaxed compared to when they were braced. Overall, this study demonstrated that muscle activation significantly affected the volunteers' responses for both mid-size males and small females during low-speed events. These results highlight the importance of developing active HBMs with relevant volunteer data in order to be more representative of live occupants. Finally, the data from this study can be used to develop active HBMs to improve their accuracy, so that the models can be used to assess occupant safety during low-speed frontal vehicle crashes. This will help improve the understanding of potential injury risk and development of effective vehicle safety systems, to reduce the number of injuries caused by vehicle crashes.

Ramp descent is a demanding task for trans-tibial amputees, due to the difficulty in controlling body weight progression over the prosthetic foot. A deeper understanding of the impact of foot function on ramp descent biomechanics is required to make recommendations for rehabilitation programs and prosthetic developments for lower-limb amputees. The thesis aim was to determine the biomechanical adaptations made by active unilateral trans-tibial amputees (TT) using a microprocessor-controlled ankle-foot prosthesis in active (MC-AF) compared to non-active mode (nonMC-AF) or elastically articulated ankle-foot device. A secondary aim was to determine the biomechanical adaptation made by able-bodied individuals when ankle motion was restricted using a custom made ankle-foot-orthosis and provide further insight into the importance of ankle dynamics when walking on ramps. Kinetic and kinematic data were recorded from nine TT’s and twenty able-bodied individuals. Able-bodied participants, ankle restriction, led to an increase in involved limb loading response knee flexion that is accompanied by the increased knee power generation during the single-limb-support phase that correlates to TTs results. TT’s use of an MC-AF reduced the ‘plantar-flexion’ resistance following foot contact allowing foot-flat to be attained more quickly. Followed by the increased ‘dorsi-flexion’ resistance which reduced the shank/pylon rotation velocity over the support foot, leading to an increase in negative work done by the prosthesis. These findings highlight the importance of having controlled ankle motion in ramp descent. Use of an MC-AF can provide TTs controlled motion for descending ramps and hence provide biomechanical benefits over using more conventional types of ankle-foot devices. / Engineering and Physical Science Research Council (EPSRC) via Doctoral Training Account (DTA) (EP/P504821/1) Chas. A. Blatchford and Sons Ltd., Basingstoke, UK provided the prosthetic hardware, prosthetist support, and facilitated the attendance of the TT participants for this study