Experimental Investigation of a Slip in High-Performance Steel-Concrete Small Box Girder with Different Combinations of Group Studs

Sensitivity Optimization of Surface Acoustic Wave Yarn Tension Sensor Based on Elastic Beam Theory

The measurement of yarn tension has a direct impact on the product quality and production efficiency in the textile manufacturing process, and the surface acoustic wave (SAW) yarn tension sensor is a good option for detecting the yarn tension. For SAW yarn tension sensors, sensitivity is an important indicator to assess their performance. In this paper, a new type of SAW yarn tension sensor based on a simply supported beam structure is studied to improve the sensitivity of the fixed beam SAW yarn tension sensor. The sensitivity analysis method based on elastic beam theory is proposed to illustrate the sensitivity optimization. According to the analysis results, the sensitivity of the SAW yarn tension sensor can be greatly improved by using a simply supported beam structure compared to the s fixed beam structure. Moreover, from the calibration experiment, the sensitivity of the simply supported beam SAW yarn tension sensor is 2.5 times higher than that of the fixed beam sensor.

Static and Fatigue Behavior of Rubber-Sleeved Stud Shear Connectors as Part of Field-Cast Ultra-High Performance Concrete Connections

Field-cast ultra-high performance concrete (UHPC) connections are an innovative and prospective solution for combining full-depth precast concrete decks and steel girders. However, previous studies show that the slip capacity of stud shear connectors embedded in UHPC cannot meet the requirements for ductile connectors by Eurocode 4, which can reduce the resistance of steel and concrete composite members. In this study, the rubber-sleeved stud shear connector, which is a composite of ordinary stud and rubber sleeve, was adopted for the field-cast UHPC connections. Push-out tests were conducted to investigate the static and fatigue behavior of the rubber-sleeved stud shear connector as part of field-cast UHPC connections. Results of static tests showed that the rubber-sleeved stud shear connector has sufficient deformation capacity and its slip capacity is 1.5 times that of the ordinary stud shear connector. Compared to ordinary stud shear connectors, UHPC with high strength and stiffness has a relatively small effect on improving the shear strength and stiffness of rubber-sleeve stud shear connectors. Results of fatigue tests showed that the rubber-sleeved stud shear connector in UHPC has similar fatigue behavior to that in normal strength concrete. Though UHPC improves the restraint to the stud deformation, the influence of rubber sleeves is still decisive in determining the fatigue behavior of rubber-sleeve stud shear connectors. In addition, based on the results of strain gauges at stud roots, it was found that the crack initiation process consumes a small proportion of the fatigue life of rubber-sleeved stud shear connectors, which is about 5%.

Experimental Investigation of Impact Concrete Slab on the Bending Behavior of Composite Bridge Girders with Sinusoidal Steel Web

Until recently, steel plate girders with corrugated steel members were used primarily as poles and girders in the construction of industrial buildings. Currently, they are also being used in the construction of bridges. Compared to traditional steel and rolled girders, steel plate girders weigh less and are more stiff, while also having a neater appearance. In this paper, the results of an experimental study are present. The aim of the study was to determine the behavior of a bridge girder with sinusoidal web geometry when subjected to a bending moment. The study was focused on a composite steel and concrete structure with pin connections, which is currently the most common solution. Three near-real scale beams were subjected to bending tests. The study found that composite corrugated-web steel beams and non-composite corrugated-web steel beams showed similar forms of failure. A reinforced concrete slab did not prevent web stress concentration at the point of connection with the flange. Furthermore, the study indicates that corrugated steel webs in bridge girders can have a much smaller thickness (less than 8 mm) compared with the traditional solution.