Ce travail traite du ballottement d'un fluide dans une cuve rectangulaire en mouvement et du couplage avec un corps flottant. Nous exposons premièrement une théorie linéaire basée sur la décomposition des mouvements dans la base des modes propres de la cuve. Pour les mouvements plus importants la théorie linéaire atteint ses limites, nous proposons un modèle de type Boussinesq et un modèle d'équations intégrales avec des conditions de surface libre complètement non-linéaires. Nous considérons également un terme d'amortissement linéarisé. Nous comparons les résultats numériques à des résultats expérimentaux pour une cuve à fond plat et pour un fond légèrement incliné. Le taux de remplissage varie également. Le couplage de la cuve avec une barge rectangulaire est réalisé par développement en série de fonctions propres et par leur raccordement aux frontières des différents sous-domaines. Tous ces résultats, numériques et expérimentaux , sont comparés dans le domaine fréquentiel et temporel. / This work focuses on the sloshing of the fluid in rectangular tanks with forced motions and of the coupling with a floating body. A linear theory is firstly given for the sloshing which is represented by the superposition of natural sloshing modes. Compared with linear theory, the extended Boussinesq-type models are used for the simulations of nonlinear sloshing motions. The fully nonlinear free surface conditions are adopted and linear damping term is considered in the model. The integral equation method with fully nonlinear free surface conditions are also applied. A flat bottom rectangular tank with different filling levels are discussed based on these numerical methods and experiences. The solutions of an inclined bottom tank are studied and compared with experimental results. The sea-keeping of a rectangular barge is modeled by a series of eigen-functions. The coupled computations of the sloshing in the tank and the sea-keeping of floating body are studied in both the frequency domain and time domain. The numerical results are compared with experimental results.

Management and control of the low back pain as an important health problem in the industrial societies necessitates to investigate how the risk of this disease is affected by aging. Since the abnormalities of the lumbopelvic kinematics are related to the existence or risk of low back injuries, the objective of this dissertation was set to find the age-related differences in lumbopelvic kinematics when performing basic trunk motions reaching to range of motion in different anatomical planes. A cross-sectional study was designed where sixty asymptomatic individuals between 20–70 years old with no confounding health condition, no current or previous highly physically demanding occupation and a body mass index between 22 and 30, were divided in five equally-sized and gender-balanced age groups, and attended two sessions of data collection to perform three repetitions of self-selected slow and fast trunk forward bending and backward return, as well as one left and right lateral bending and axial twist. Following an extensive literature review, the lumbar contribution (LC) to the trunk motion, the mean absolute relative phase (MARP) between the thoracic and pelvic motions as well as variation in MARP under repetitive motions, denoted by deviation phase (DP) were selected and used for the assessment of age-related differences in lumbopelvic kinematics during forward bending and backward return tasks. Lumbopelvic kinematics during the lateral bending and axial twist tasks were assessed using the lumbar and pelvic ranges of motion (ROMs) and coupled motion ratios (CMRs) as respectively the maximum flexion/rotation in the primary (i.e., intended) and the secondary (i.e., coupled) planes of trunk motion, where the latter was normalized to the conjugate ROM for better comparison. The results showed age-related differences between the age groups above and under 50 years of age generally. A smaller LC during the forward bending and backward return tasks were observed in the older versus younger age groups, suggesting that the synergy between the active and passive lower back tissues is different between the older and younger people, which may affect the lower back mechanics. Also, smaller MARP and DP suggesting a more in-phase and more stable lumbopelvic rhythm were observed in the older versus younger age groups, which may be a neuromuscular strategy to protect the lower back tissues from excessive strain, in order to reduce the risk of injury. Furthermore, the coupled motion of lumbar spine in the transverse plane during the lateral bending to the left, and the coupled motion of pelvis in the sagittal plane during the axial twist to the right were larger in older versus younger age groups. In summary, the lumbopelvic kinematics changes with aging, especially after the age of 50 which implies alterations in the active and passive tissue responses to the task demands, as well as the neuromuscular control patterns. Drawing a conclusion regarding ii the effect of aging on the risk of low back pain from these results requires a further detailed knowledge on age-related differences in spinal active and passive tissue properties.

Steel Catenary Riser (SCR) is a popular solution for a floating production facility in the deep and ultra-deep ocean. In the analysis of SCR, the behavioral characteristics are investigated to check the failure modes by assessing the magnitude and the frequency of the stress and strain which SCR goes through in time series. SCR is affected by the motions of connected floating production facility and exciting environmental loads. The driven force and motion of SCR has an interaction with seabed soil which represents the stiffness and friction force where SCR touches the seabed. Dynamic response of SCR is primarily caused by the coupled motion of floating structure. The displacement of floating structure is often large and fast enough to cause short cycles of negative and positive tension on SCR. The interaction between SCR and seabed is concentrated at the touchdown zone resulting into the compression and corresponding deformation of pipeline at the position. This paper presents models of floating production facilities and connected mooring lines and SCRs in 100-year hurricane environmental loads and seabed, focusing on the motional characteristics of SCR at the touchdown zone. In time series simulation, the model of SCR is first analyzed as a pipeline with indefinite elasticity so that the SCR does not fail even if the exciting loads exceed the property limit of SCR. Then the SCR design is manually checked using criteria for each failure mode to estimate the integrity.