Adhesion and Adhesives Edited by Dr. R. Houwink and Dr. G. Salomon. Vol. 1: Adhesives. Second, completely revised edition. Pp. xvi + 548. (Amsterdam, London and New York: Elsevier Publishing Company, 1965.) 135s.

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Adhesion and Adhesives

COMMITTEE MANDATE Concern for crack initiation and growth under cyclic loading as well as unstable crack propagation and tearing in ship and offshore structures. Due attention shall be paid to practical application and statistical description of fracture control methods in design, fabrication and service. Consideration is to be given to the suitability and uncertainty of physical models. The work shall be coordinated with that of Committee V.2.

Fatigue and Fracture

This report contains the findings of a study on fatigue resistance of cantilevered signal, sign, and light supports. Recommended specifications for the fatigue-resistant design of these structures are included. The contents of this report will be of immediate interest to bridge and structural engineers, traffic engineers, and manufacturers. The research determined that, for a typical sign or signal support structure, galloping is the primary cause of vibrations that may result in fatigue damage. It was also determined that the number of structures observed to be galloping in field applications is low. Much variation in the detailing of connections was found, and several details of low fatigue resistance are in use. The research suggests that, through changes in the recommended design wind loads used for design of these structures and avoidance of fatigue-susceptible details, the probability of failure of these structures may be reduced. In addition, the research suggests that mitigation of wind-induced vibrations of structures, once they are observed in the field, may also be a desirable action. The report recommends additional research in this area and provides guidance that designers may consider pending any formal changes to design specifications by the American Association of State Highway and Transportation Officials.

Fatigue-resistant design of cantilevered signal, sign, and light supports

Fatigue analysis and life prediction of bridges with structural health monitoring data — Part II: application

SUMMARY: This paper investigates the effect of the composite action on the seismic performance of steel special moment frames (SMFs) through collapse. A rational approach is first proposed to model the hysteretic behavior of fully restrained composite beam-to-column connections, with reduced beam sections. Using the proposed modeling recommendations, a system-level analytical study is performed on archetype steel buildings that utilize perimeter steel SMFs, with different heights, designed in the West-Coast of the USA. It is shown that in average, the composite action may enhance the seismic performance of steel SMFs. However, bottom story collapse mechanisms may be triggered leading to rapid deterioration of the global strength of steel SMFs. Because of composite action, excessive panel zone shear distortion is also observed in interior joints of steel SMFs designed with strong-column/weak-beam ratios larger than 1.0. It is demonstrated that when steel SMFs are designed with strong-column/weak-beam ratios larger than 1.5, (i) bottom story collapse mechanisms are typically avoided; (ii) a tolerable probability of collapse is achieved in a return period of 50years; and (iii) controlled panel zone yielding is achieved while reducing the required number of welded doubler plates in interior beam-to-column joints. © 2014 John Wiley & Sons, Ltd.

Modeling of the composite action in fully restrained beam‐to‐column connections: implications in the seismic design and collapse capacity of steel special moment frames

Continuity Plate Detailing for Steel Moment-Resisting Connections

The propagation of long cracks under constant amplitude cyclic loading is studied in complex welded box beams made of high strength low alloy (HSLA) steel. The 8 x 1 x 0.7 m box beams were designed to simulate the cellular structure of a double hull ship but the results of the experiments are equally applicable to other box systems such as bridges. These experiments were designed to evaluate the residual fatigue life after a significant fatigue crack has formed. After testing, residual stresses were measured on two box beams using the standardized strain gage hole-drilling method. The experiment results demonstrated the good crack tolerance of cellular structures. The residual life of a box beam (after a welded detail has failed) was significant. The crack driving force was evaluated using finite element modeling. Reasonable correlation between these large scale tests and the fatigue crack growth rate from small compact specimen was obtained only with models that included the effects of crack closure due to residual stresses. Linear elastic fracture mechanics proved to be sufficient to predict the behavior of long cracks in this case.

Behavior of Long Fatigue Cracks in Cellular Box Beam

Data regarding service performance and durability of modular bridge expansion joint systems were gathered through a comprehensive literature review, survey of transportation agencies, and field observations. Typical service life and desired service life targets are discussed. Maximum movement and rotation demands are given with respect to three axes. Performance and durability problems include problems that can be traced to poor design and/or installation, wear and tear of elastomeric parts, and fastener loosening and fatigue cracking of the metal parts. Fatigue cracking has been addressed in previous research. Guidance on design, detailing, specifications, installation, and maintenance is discussed, which should reduce the problems in the first group. Problems with the elastomeric parts and fasteners are best addressed through performance tests on the modular bridge joint systems as a system. Two system performance tests, an opening movement/vibration test, and a seal push-out test are suggested for the ...

Design, Specification, Installation, and Maintenance of Modular Bridge Expansion Joint Systems

In order to determine equivalent static pressures for fatigue loads on cantilevered highway sign support structures a cantilevered variable message sign (VMS) located along Interstate 80 westbound at mile marker 48.5 in northern New Jersey was continuously monitored for three months. The structure was instrumented with strain gages, pressure transducers, and a wind sentry. All the data was collected with a Campbell Scientific CR9000 digital data acquisition system. A cellular phone transceiver enabled remote communication with the data logger. The system and instrumentation was powered with solar powers and marine batteries. Short-term testing was performed on the structure to determine the dynamic characteristics such as stiffness, natural frequency, and percent of critical damping. Results of the short-term test indicated that the stiffness was 0.24 kN/mm, the first and second mode natural frequencies were 0.87 cycles/s and 1.22 cycles/s respectively, and the percent of critical damping for the first and second modes were 0.57 percent and 0.25 percent respectively. Long-term monitoring was performed to capture the structure's response to natural wind gusts, galloping, and truck-induced wind gusts. This data would then be used to determine appropriate fatigue design wind loads for future sign support structures. During the three months of monitoring the structure did not experience galloping, which is a phenomena highly dependent on location. A galloping design pressure of 1000 Pa was recommended based on previous research. The summer months, which is when the structure was monitored, were not conducive to the strongest natural wind patterns in northern New Jersey. The highest natural wind speed that was recorded was 7.5 m/s. It is believed that much stronger winds are present in winter and spring, therefore a natural wind gust design pressure of 250 Pa was recommended. Truck-induced gusts were measured and a linear gradient for the truck-induced gust design pressure was determined. The truck-induced gust design pressure ranged linearly from 1760 Pa at 0 to 6 m above the surface of the road to 0 Pa at 10.1 m and over.

Fatigue Related Wind Loads on Highway Support Structures

Experimental and analytical research was recently performed to develop performance-based specifications and commentary for the fatigue design of modular bridge expansion joints (MBEJ). The resulting proposed fatigue-design and test specifications resulting from this research are discussed. These specifications are intended for integration into the present AASHTO Load and Resistance Factor Design (LRFD) Bridge Design Specifications. For consistency with the bridge design specifications, the proposed MBEJ fatigue-design specifications used the same fatigue-design truck as was used by the present AASHTO bridge specifications. However, one important modification of the AASHTO truck loading for MBEJ is the explicit recognition that the rear axles of the HS series trucks actually represent tandem axles. A simplified method to estimate the distribution factor (i.e., the fraction of the range of the design-wheel load assigned to a single "centerbeam") is recommended. Dynamic impact on both the vertical and horizo...

Robert J. Dexter

Papers

Continuity Plate Detailing for Steel Moment-Resisting Connections

Behavior of Long Fatigue Cracks in Cellular Box Beam

Design, Specification, Installation, and Maintenance of Modular Bridge Expansion Joint Systems

Fatigue Related Wind Loads on Highway Support Structures

Fatigue Design of Modular Bridge Expansion Joints