Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 3081 for “"Stiffness"”.
-
Factors affecting the initial stiffness and stiffness degradation of cohesive soils
… role of the following factors on both initial stiffness and small strain (Ea<O.1%) non-linearity in undrained triaxial compression: consolidation stress level (0.5-12 ksc), overconsolidation ratio ( 1,2,4,8), pre-shear consolidation stress path (loading vs. unloading), pre-shear lateral stress …
-
Impact of Surface Stiffness on Lower Limb Stiffness and Symmetry During Gait
… that affects performance and injury risk is limb stiffness. Limb stiffness is the body's resistance to deformation when moments and forces are applied to it. The body has been shown to be modeled as a spring mass system that can restore and reuse energy. This is associated with the stretch …
-
Inflammation and arterial stiffness
Arterial stiffness is one of the earliest detectable manifestations of adverse structural and functional changes within the vessel wall. It is well known that increased large artery stiffness independently predicts the cardiovascular risk in a variety of populations. The identification of …
-
Shock isolation using switchable stiffness
This study investigates a novel stiffness control strategy applied to the problem of shock isolation. This is based on the principle that the stiffness and mass are the principal physical properties that control the passive system shock response. The problem of shock response control is divided in …
-
Clinical assessment of arterial stiffness
Increased arterial stiffness is associated with ageing, cardiovascular disease diabetes and renal failure. The aims of this thesis were to investigate the reproducibility of a tissue Doppler imaging (TDI) based ultrasound system to calculate indices of arterial stiffness, and to investigate changes …
-
Musculotendinous stiffness and muscle function
Musculotendinous stiffness or elasticity is difficult to measure in vivo. Therefore, various procedures have been used in an attempt to quantify the contribution of the elastic properties of muscle and tendon to stretch shortening cycle performance. The results are variable, perhaps as a result of …
-
Switchable stiffness scanning microscope probe
… thesis investigates the new concept of a dual stiffness scanning probe with respect to biological applications and determines the resulting requirements for the scanning of soft bio samples, such as low-pressure contact. On this basis, an in-plane AFM probe that is specifically tailored to the …
-
Horizontal Stiffness of Wood Diaphragms
… investigation was conducted to study the stiffness of wood diaphragms. Currently there is no method to calculate wood diaphragm stiffness that can reliably account for all of the various framing configurations. Diaphragm stiffness is important in the design of wood framed structures to …
-
Large Artery Stiffness: Genes and Pathways
Aortic stiffness underlies systolic hypertension, promotes heart failure and is associated with in- creased cardiovascular morbidity and mortality. It is regarded as a primary driver of left ventricular hypertrophy and aortic aneurysms and is linked to the pathogenesis of cognitive impairment, …
-
Tailoring stiffness of deployable origami structures
Embargo set by: Seth Robbins for item 98713 Lift date: 2019-03-01T17:03:32Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system
-
Stiffness matrices of carbon nanotube structures
… modeling study was done to determine the stiffness matrices of the lattice structure of graphene, the planar building block of carbon nanotubes. Through continuum linear elastic analysis and a displacement-based finite element method, the global in-plane stiffness matrix for an arbitrary …
-
Stiffness Model of a Die Spring
… research is to determine the three-dimensional stiffness matrix of a rectangular cross-section helical coil compression spring. The stiffnesses of the spring are derived using strain energy methods and Castigliano's second theorem. A theoretical model is developed and presented in order to …
-
Investigating the Interplay between Inflammation and Matrix Stiffness: Evaluation of Cell Phenotype and Cytoplasmic Stiffness In Vitro
… that subsequently lead to an increase in tissue stiffness and changes to ECM architecture. Such changes to the mechanical properties of the cellular microenvironment affect the cytoskeletal arrangement, migration and adhesion of both the parenchymal cells, as well as immune response cells, which …
-
Stiffness Analysis of Cable-Driven Parallel Robots
The aim of this thesis is the stiffness analysis of cable-driven parallel robots. Cable-driven parallel robots have drawn considerable attention because of their unique abilities and advantages such as the large workspace, light weight of cable actuators, easy disassembly and transportation of the …
-
AORTIC STIFFNESS MODIFICATIONS AFTER ENDOVASCULAR AORTIC REPAIR
… have emerged, particularly related to aortic stiffness, a known predictor of cardiovascular morbidity and mortality. Objective: This study aimed to evaluate the modifications in aortic stiffness in patients undergoing endovascular aortic repair by measuring pulse wave velocity (PWV) using …
-
Cooperative impedance control with time-varying stiffness
… force and control a grasped object's apparent stiffness, damping, and inertia. Conventional impedance control practices have focused on position-based manipulators - which are inherently non-compliant - using constant, task-dependent impedances. In the event of large trajectory tracking errors, …
-
Pneumatic variable stiffness soft robot end effectors
… This research presents the design of a variable stiffness, soft, three-fingered dexterous gripper. The gripper uses contractor pneumatic muscles to control the motion of soft fingers. The soft nature of the gripper means it can deform if it collides with obstacles, and because grasping forces are …
-
Small strain stiffness of fine grained soils
Dynamic measurements of very small strain stiffness (c - 0.001% and less) were carried out both in the laboratory, using piezoceramic bender elements of the type developed at the Norwegian Ceotechnical Institute and at the University College of North Wales, and in situ, using surface wave …
-
Analysis of Tow-Placed, Variable-Stiffness Laminates
… which is composed of such plies will have stiffness properties which vary as a function of position. Previous work had modelled such variable-stiffness laminae by taking a reference fiber path and creating subsequent paths by shifting the reference path. This thesis introduces a method …
Page 1 of 155