Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 130-136). Also available via the Internet.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 111-114). Also available via the Internet.

Thesis (M.S.)--George Mason University, 2009. / Vita: p. 42. Thesis director: Girum Urgessa. Submitted in partial fulfillment of the requirements for the degree of Master of Science in Civil, Environmental, and Infrastructure Engineering. Title from PDF t.p. (viewed Oct. 12, 2009). Includes bibliographical references (p. 39-41). Also issued in print.

Two distinct sections of research are presented in this thesis. The first section summarizes research conducted on laboratory-built floors. Floors were built and tested to determine the plywood contribution to increasing the bending stiffness, number of joists effective in resisting applied load, and calculation of fundamental frequency. The second section summarizes research conducted on in-situ floors. Procedures were developed to numerically integrate acceleration and velocity data to obtain displacement values. Tests were conducted on 86 subjectively rated wood floors to determine average frequency and peak displacement values. From these tests, a design criterion was developed to predict acceptability of a wood floor system to vibrations. / Master of Science

This thesis describes the effects of coefficient of variation (COV) of joist modulus of elasticity (MOE), floor mass and stiffness, imposed load, and boundary conditions on the floor vibrational performance. Three main parameters used to describe the vibration are resonant frequency, damping ratio, and root mean square (RMS) acceleration. The results showed that COV of joist MOE affected the fundamental frequency, and had no significant effect on damping ratio and RMS acceleration. The floor mass and stiffness affected all the three parameters to different degrees. Imposed load affected most of the vibrational parameters. The boundary conditions investigated affect the mode 2 resonant frequency, but have no significant effect on the damping ratio and RMS acceleration. In addition, the load sharing capacity was evaluated in terms of the percentage of load carried by each joist within a floor. / Master of Science

This thesis is based on research by the VPI Agricultural Engineering Department in residential floor structures. Slope-deflection equations and computer programs were developed for theoretically analyzing continuous non-prismatic T-beams. Residential floor systems were treated as a series of three-span continuous T-beams. Cross-sectional area of the stem of the T-beam was doubled over interior supports and for 3 ft. on either side. Computer programs were used for calculating moment, shear, deflection, and rotation over supports for beams with simply supported ends and with one end cantilevered. The computer was also used for determining span ratios that would result in equal maximum deflections when all three spans were subjected to uniformly distributed loads. Several tests were conducted on a full-scale 8 ft. by 48 ft. floor section. Deflection from the experimental tests on continuous joist alone and with plywood subfloor were statistically compared with theoretical deflections. In one case the theoretical equation did not adequately describe the center span and had to be rewritten in order to show no significant difference between theoretical and experimental deflection. In one experiment symmetrical end spans did not act as replicates of each other 2 in which case the maximum experimental deflection was significantly larger than the theoretical deflection. In all other cases there was no significant difference in theoretical and experimental deflections. It would require 33.9% more timber in nominal 2 in. thick lumber as simple beams to provide equal strength and stiffness as the experimental three-span continuous beam. / M.S.

This thesis presents the effects of cutouts in joists on the dynamic performance of wood floors. Ten floors and four-floor joist types were used to evaluate the vibrational response of wood floors with and without cutouts in the joists. Each floor was also subjected to different boundary conditions and imposed load during the evaluation. Two types of tests were performed on the floors, a free vibration test and a drop weight test. Data collected from these tests were used to determine several dynamic variables. These variables are the peak displacement, peak acceleration, resonant frequencies, separation of resonant frequencies, root-mean-squared (RMS) acceleration, log-decrement damping ratio, and modal damping ratios. Included in the thesis are the results of a static test (load sharing) performed on the floors with and without cutouts in the joists. / Master of Science