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 32 for “"effective stiffness"”.
-
On the Effective Stiffness of Slender Concrete Masonry Walls
… found to be overly conservative. The calculated effective stiffness term, EIeff, which is used to determine the secondary moment due to wall deflection, was noted as a potentially significant cause of this conservatism. In this thesis, the degree to which the effective stiffness term contributes …
-
Multiple Wave Scattering and Calculated Effective Stiffness and Wave Properties in Unidirectional Fiber-Reinforced Composites
… are investigated in this study to calculate the effective static stiffness (axial shear modulus, m) and wave properties (axially shear wave speed, B and attenuation, Y) in composites. For simplicity only out-of-plane shear waves are modeled propagating in a plane transverse to the fiber axis. …
-
A study of two dimensional braided composites
… maximum fiber volume fraction is also obtained. Effective stiffness of 2-D braided composite is obtained in a close form by the analysis of elastic deformation energy in repeat-unit-cell of braided composites. Effective stiffness consists of contributions of axial yarn, braiding yarn, and matrix …
-
Peridynamic Investigation of Stress-Strain Response and Fracture Behavior Variations in Micro-CT Images of Mock Energetic Nanocomposites
… cases suggest that the overall sample had an effective stiffness of 4.396 +/- 1.153 GPa, though this varied significantly between images and image groupings. In addition, the effective stiffness of image groupings varied from 2.5 GPa to approximately 5 GPa as image number increased. These …
-
Experimental Evaluation of Composite Action of Steel Box Truss Towers in Flexure
… action was characterized by comparing the effective stiffness shown in testing to the stiffness of a similar specimen with fully developed composite action. The parametric study was used to develop a relationship between connection spacing and tower stiffness. Experimental results indicated …
-
Role of Intrinsic and Reflexive Dynamics in the Control of Spinal Stability
… and control of active paraspinal muscle stiffness (i.e., trunk stiffness). The two major components of active muscle stiffness include the immediate stiffness contribution provided by the intrinsic stiffness of actively contracted muscles, and the delayed stiffness contribution provided …
-
Exploration of Wood DCB Specimens Using Southern Yellow Pine for Monotonic and Cyclic Loading
… were computationally investigated because of the stiffness difference between latewood and earlywood growth and the grain angle along the length of the beams. The grain angle and the stiffness difference between latewood and earlywood growth caused the effective stiffness, (ExxI)eff, to vary along …
-
Nanomechanics model for static equilibrium
… of both zigzag and armchair and then their effective stiffness were estimated. Those designed nanotubes are woven into fabric composites, which can be used in various military applications including body armors, armored vehicles, and infantry transportation vehicles because advanced …
-
Development of Magnetorheological Elastomer System for Adaptive Vibration Isolation
… were utilized to generate adaptability (variable stiffness) to the AB system. The investigations of this project were fundamental and developmental studies ranging from material synthesis, material characterization, theoretical studies, design and fabrication of the AB system, and large-scale …
-
The functional role of tectorial membrane poroelasticity in cochlear mechanics
… that systematically and reversibly alter TM stiffness and viscosity. Increasing TM viscosity or decreasing stiffness reduces longitudinal spread of mechanical excitation, thereby coupling a smaller range of best frequencies, which would sharpen tuning. In contrast, increasing viscous loss or …
-
Effective mechanical Properties of material models with random heterogeneities
… heterogeneities. We start by investigating the effective elastic properties of one-, two-, and three-dimensional rectangular blocks whose Young's modulus varies spatially as a lognormal random field. We decompose the spatial fluctuations of the Young's log-modulus F = In E into first- and …
-
Cell migration and alignment on mechanically controlled environment
… First study is a cell migration behavior on stiffness controlled three-dimensional in vitro environment. The continuous stiffness gradient 3D environment is provided by the effective stiffness on a PDMS wavy pattern, and the relationship between stiffness gradient and the cell migration is …
-
An investigation of the contribution of the multi-joint arm stiffness to the motor control defecit [sic] experienced in ataxia
… to what extent ataxia is cause by abnormal effective stiffness. Because ataxic patients do not exhibit deficits in strength or postural maintenance, we hypothesize a priori that the measured stiffness of ataxic subjects will be normal. We test this by conducting postural stiffness study on …
-
Development and Characterization of a Mechanically Prestressed Piezoelectric Composite
… to define the center displacement constant and effective spring constant of the unimorph. These parameters not only allow designers to predict the displacement that will occur in response to a given electric field or tensile load, but also to allow for comparison with various devices. In the …
-
Large-strain piezoelectric actuators using controlled structural buckling
… pronounced nonlinearity in output impedance; the effective stiffness viewed from the output port varies as a function of output displacement, which can be a useful property for those applications where actuator stiffness needs to vary. Buckling is controlled with phased activation of the input …
-
Acoustic Metamaterials at the Microscale
… of extreme static mechanical properties such as stiffness, Poisson’s ratio, or strength. However, dynamic and acoustic properties of micro-architected materials remain largely unexplored, partially because it is challenging to measure their response at these scales. Dispersion resulting from …
-
Experimental determination of cell adhesion and proliferation response to substrata thickness
… has been conducted on the effect of substrata stiffness on cell behavior, but there has been no systematic study of the effect of varying substrata thickness, and its correlation to a substratum's effective stiffness that a cell feels. Furthermore, there have been differing views on what the …
-
Instability-induced transformation of interfacial layers in composites and its multifunctional applications
… material has an essential influence on the effective properties and behavior of the composite. Hence, in this research, the principles and mechanics of interfacial layer instabilities are purposely designed to achieve sudden pattern transformations in the composite structure to generate new …
-
Investigation of several aspects of the vibration characteristics of steel member-supported floors
… The four aspects are: 1) the number of tee-beams effective in resisting a heel-drop impact for steel joist and steel beam-concrete slab floors, 2) the effective moment of inertia of steel joist and joist-girder members, 3) the ability of joist seats to provide composite behavior between the …
-
Fe Modeling In Support Of Vibration Based Damage Detection In Bridges
… of defining a relationship between substructure stiffness degradation and frequency and mode shape modulation induced by damage. The relationship is explored through finite element modeling of primarily an experimental representation of a three-span concrete bridge structure located at the …
Page 1 of 2