Master of Science / Department of Architectural Engineering and Construction Science / Kimberly W. Kramer / In 2006, a research project was being carried out by architects at architecture/engineering firm Cannon Design involving an optimum bay size for a hospital. RISA computer modeling was used to explore a set of lateral force resisting system (LFRS) options for a building based on this optimum bay size and importance category. The structural material was first narrowed down to steel, and then moment frames and braced frames are examined. The LFRS was narrowed down to braced frames, discarding moment frames due to their inordinate story drift. Of the different types of braced frames, the study further narrowed the LFRS system to chevron braced frames. Then the precise arrangement of braces for a particular building size using this bay system was examined. The steel material cost of the final system was compared to a system that only included members sized for gravity loads to demonstrate the rough amount of cost that a lateral system can add to a building.

We consider first the single-track bicycle model and state relations between the tires’ lateral forces and the turning radius. From the tire model, a relation between the lateral forces and slip angles is obtained. The extra rolling resistance forces from cornering are by linear approximation obtained as a function of the slip angles. The bicycle model is validated against the Magic-formula tire model from Adams. The bicycle model is then applied on an optimization problem, where the optimal velocity for a track for some given test cases is determined such that the energy loss is as small as possible. Results are presented for how much fuel it is possible to save by driving with optimal velocity compared to fix average velocity. The optimization problem is applied to a specific laden truck. / Vi betraktar först den enspåriga cykelmodellen och ställer upp samband mellan däckens sidokrafter och kurvradien. Genom däcksmodellen fås ett samband för hur sidokrafterna beror av slipvinklarna. De extra rullmotståndskrafterna för kurvor fås via linjär approximation som funktion av slipvinklarna. Cykelmodellen valideras mot en däcksmodell från Adams. Cykelmodellen tillämpas sedan på ett optimeringsproblem där den optimala hastigheten längs en bana för några givna testfall bestäms så att energiförlusten blir så liten som möjligt. Resultat presenteras för hur mycket bränsle det är möjligt att spara genom att köra med optimal hastighet jämfört med fix medelhastighet. Optimeringsproblemet tillämpas på en specifik lastad lastbil.

The prevalence of knee osteoarthritis, a degenerative joint disease characterized by the degradation of articular cartilage, is correlated with the rise in obesity. The rising rates of obesity in children and adults highlight the need for identifying a sustainable physical activity that promotes fitness while mitigating initiation and progression of osteoarthritis. The objective of this study was to determine an effective rehabilitation and lifelong fitness sustainment exercise regimen that minimize risk of osteoarthritis in individuals with high body mass index (BMI). The aim was to examine knee medial and lateral contact forces in gait and cycling training. Gait at self-selected speeds and cycling at moderate resistance were studied using motion analysis in normal BMI and high BMI participants. Individuals with high BMI exhibited abnormal kinematics and increased kinetics in gait but neutral knee abduction-adduction angles, lower knee contact forces, and balanced mediolateral force distribution in cycling. The combination of maladaptive kinetics (excessive cartilage loading) and altered kinematics (primarily knee adduction angles) observed in gait for the high BMI cohort demonstrate the profound adverse effect of weight bearing and impact exercises on knee biomechanics. Exercise rehabilitation modalities should aim to minimize cartilage loading, correct altered knee angles, and prioritize balanced mediolateral force distributions in individuals with high BMI. Cycling, a non-weight bearing and low impact exercise, addresses all these factors because it constrains kinematic patterns with the pedals and carries significant body weight on the saddle.