An improved multi degree-of-freedom direct shear device has been designed and constructed to test interfaces and joints under pore water pressure. Any two structural (concrete, steel, wood) or geologic (soil, rock) materials may be tested in the device as long as the top specimen is solid. The apparatus is designed to hold a 7.5-inch diameter 3-inch thick upper sample and a 9-inch diameter 3-inch thick lower sample. A normal stress of 400 psi (2.7 MPa) and a shear stress of 550 psi (3.9 MPa) can be developed at the interface. Test loading may be static, quasi-static, or cyclic, and constant or variable stiffness loading is available. A stiff reaction frame was designed to house the device and is described. The electro-hydraulic system is capable of supporting cyclic testing at 30 Hz. A new computer-controlled data acquisition and control system is also described.

published_or_final_version / abstract / Civil Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / Orthopaedics and Traumatology / Master / Master of Philosophy

No description available.

No description available.

No description available.

Tension and Compression force deformation data from laboratory tests of angle segments are used to generate moment rotation curves for the following bolted partially restrained connections: (1) top and seat angle, (2) double web angle, and (3) top and seat angle with double web angles. The force deformation and moment rotation curves are analytically described by a four parameter formula which provides the basis for the analytical connection model. These connection models consist of rigid bars and nonlinear springs representing the angle segments in either tension or compression. Design curves giving the four parameters of the moment rotation curves are generated for the double web angle connection. These parameters are primarily a function of the angle thickness, gage length of the angle legs in flexture, and the number of bolts in the connection. Comparisons of derived moment rotation curves are made with published results of full scale tests.

Results of tension and compression tests on angle segments are used to generate moment-rotation curves for welded-welded double framing angle connections. The beam line concept is then used to determine the connection moments for connection depths of 18 to 32 inches. With the connection moments known, the two welds, denoted as Weld A and Weld B in the AISC Manual Table IV are evaluated. Because the analytical model used to generate the weld sized published in the AISC Manual and analytical model used in this research differ, it was found that the capacities of the connection designs in the AISC Manual for Weld B have factors of safety ranging from 2.5 to 3.0. Design aids are included which give the connection moments for a variety of designs as a function of the length to depth ratio of the beam for the case of uniform loading.

Joint mobility is dependent on comfort, thus pain is associated with mobility. This study examined the relationship between pain perception and joint mobility in arthritis patients before and after total knee arthroplasty. Pain perception was indicated by pain intensity, pain distress and pain expectation; joint mobility was represented by the degree of knee joint flexion. Visual analogue scales were used for pain intensity, pain distress and pain expectation; knee joint flexion as measured using a goniometer. Data were collected on 24 subjects preoperatively (T1), immediately postoperatively (T2) and forty-eight to seventy-two hours postoperatively (T3). Twenty-four subjects participated in the study. Significant paired t-test resulted for joint flexion at T1 and T3 and pain expectation at T2 and T3. Pearson product-moment correlation coefficients were significant for pain intensity and pain distress at all three times, pain intensity and joint flexion at T1 and pain intensity at T1 and at T2.

No description available.