Current Issue : July - September Volume : 2018 Issue Number : 3 Articles : 5 Articles
The rising interest in sustainable modes of transportation has increased demand for the design and implementation of bicycle\nfacilities in the United States. However, as compared to the vehicular mode, bicycle facilities have relatively less development,\nresearch, and understanding. The availability of a bicycling simulator has the potential to contribute to the understanding of\nbicycle facility design and bicyclist behavior. The design and construction of a bicycling simulator differs from a driving simulator\nin many ways. A bicycling simulator requires interfaces for bicycle speed, braking, and steering angle as well as a visual interface.\nIn addition, a representation of a real-world network, including pavement, buildings, the sky and background, and fixed and\nmoving objects, needs to be modeled using a simulator engine. This paper presents the details of the ZouSim bicycling simulator\ndevelopment and the tradeoffs associated with various design decisions, such as the choice of a steering sensor and graphical\ndisplay. A sample application of a wayfinding and detection markings study illustrates the use of ZouSim. The authors hope that\nthis article will encourage other researchers who conduct research in sustainable cities to explore the use of bicycle simulators for\nimproving bicycle facility design and operations....
Punching shear failure of flat concrete slabs is a complex phenomenon with\nbrittle failure mode, meaning sudden structural failure and rapid decrease of\nload carrying capacity. Due to these reasons, the application of appropriate\npunching shear reinforcement in the slabs could be essential. To obtain the\nrequired structural strength and performance in slab-column junctions, the\neffect of the shear reinforcement type on the punching resistance must be\nknown. For this purpose, numerous nonlinear finite element simulations were\ncarried out to determine the behavior and punching shear strength of flat\nconcrete slabs with different punching shear reinforcement types. The efficiency\nof different reinforcement types was also determined and compared.\nAccuracy of the numerical simulations was verified by experimental results.\nBased on the comparison of numerical results, the partial factor for the design\nformula used in Eurocode 2 was calculated and was found to be higher than\nthe actual one....
This study analyzes the National Bridge Inventory in the U.S. to determine the\nrelative structural deficiencies of bridge materials, comparing between the overall national values\nand each state, geographically. The analysis considers the most common bridge construction\nmaterialsââ?¬â?concrete, steel, and prestressed/post-tensioned concrete. The results suggest need to\nreassess the efficacy of best performance practices for steel bridges and for states with structural\ndeficiencies above the national average. Geographic consistency of structurally deficient bridge\ndensity with population density shows need to improve intervention strategies for regions with\nhigher levels of service usage. The study also compares the relative operational lifespan of bridge\nmaterials in each state. The average structurally deficient bridge ages are lower than the 75-year\nlife-cycle expectancy. Prestressed/post-tensioned concrete bridges reveal relatively lower lifespan.\nOver time, concrete and steel bridges show some gradual improvement with decreasing percentage\nof structural deficiency and increasing lifespan. Prestressed/post-tensioned concrete bridges reveal\nshifting earlier accumulation of structural deficiency for a particular age group. The study also reveals\nrelative climate effects. Climate conditions correlate differently with the structural deficiency and life\ncycle of bridge materials in each state. Structurally deficient bridge densities show correlation with\nclimate maps, especially under colder and moist conditions....
The aim of this paper is to put forward a design model for multilayer free damping structures. It sets up a mathematical model\nand deduces the formula for its structural loss factor ...
This study uses the in-structure recordings to investigate the vibration characteristics\nof a 51-story steel high-rise building in response to a major earthquake,\ntyphoon and ambient vibrations. This presents an opportunity for us\nto compare the building behaviors, especially their modal properties under\ndifferent types of excitation. First, we use a two-stage regression procedure to\nobtain the relations of the building response, including peak floor acceleration\nand velocity as a function of the wind speed and floor height of the building.\nSecondly, the structural dynamic characteristics of the high rise building, including\nthe transfer functions and natural frequencies, excited by the Chi-Chi\nearthquake, Typhoon Aere, and ambient vibrations are also determined and\ncompared. As a result, from the formulas for building response, the predicted\npeak floor acceleration is higher in the lateral (EW) component than in the\nlongitudinal (NS) component. This is probably due to the greater stiffness of\nthe building in the longitudinal direction than in the lateral direction. In addition,\nafter having identified the 1st, 2nd, and 3rd natural frequencies using the\nrecorded data from the earthquake, typhoon and ambient vibrations, the\nranking of the fundamental natural frequencies from low to high is the\nChi-Chi earthquake, Typhoon Aere and the ambient vibrations. This means\nthat greater excitation forces of the earthquake have resulted in lower natural\nfrequencies than that produced by the typhoon and ambient vibrations...
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