scholarly journals Effect of different strengthening techniques on the behavior of one-way continuous slab with insufficient length of development

2021 ◽  
Vol 1973 (1) ◽  
pp. 012119
Author(s):  
Ruqayah D. Al-Shebawi ◽  
Labeeb S. Al-yassri
Keyword(s):  
Continuous Slab

An analytical method for full-range mechanical behavior of continuous slab-deck in multi-span simply supported concrete bridges

2021 ◽  
pp. 136943322110427
Author(s):  
Xiang Zhang ◽  
Quan-Sheng Yan ◽  
Bu-Yu Jia ◽  
Zheng Yang ◽  
Ying-Hao Zhao ◽  
...  
Keyword(s):  
Nonlinear Analysis ◽  
Full Range ◽  
Scale Model ◽  
Axial Stiffness ◽  
Spring Model ◽  
Analysis Model ◽  
Rotational Spring ◽  
Simply Supported ◽  
Continuous Slab ◽  
Rotational Spring Model

Connecting the ends of girders with a continuous slab-deck to make a multiple-span simply supported girder bridge provides many benefits, but there is no suitable nonlinear analysis model which considers continuous slab-deck cracking under tension and bending. In this article, the rotational spring model is further refined to replace the restraining effects at both ends of the girder by the simplified mechanical model associated with axial stiffness, bending stiffness, and shear stiffness. Then, it is introduced into the analysis of continuous slab-deck. The more accurate rotations and displacements of both ends of continuous slab-deck are obtained to investigate the more precise moment and tension of the continuous slab-deck. Furthermore, this article presents an improved nonlinear analysis model of continuous slab-deck based on a detailed boundary rotational spring model. The displacements of important positions and the strain of key components in continuous slab-deck after cracking are investigated by numerical analysis and full-scale model test to verify the accuracy of the proposed nonlinear analysis model. The result shows that the nonlinear analysis model presented in this article could successfully evaluate the depth of cracks and the stress of rebars in continuous slab-deck, and it is instructional in predicting the cracking state of the continuous slab-deck and the reinforcement design.

Anatomical analysis of ventrolateral thalamic input to primate motor cortex

1976 ◽  
Vol 39 (5) ◽  
pp. 1020-1031 ◽  
Author(s):  
P. L. Strick
Keyword(s):  
Motor Cortex ◽  
Retrograde Transport ◽  
Sensory Cortex ◽  
Central Sulcus ◽  
Thalamic Neurons ◽  
Thalamic Input ◽  
Continuous Slab ◽  
Ventrolateral Thalamus ◽  
Point To Point ◽  
Somatic Sensory Cortex

1. The origin and topographical organization of input to the arm area of the primate motor cortex from the ventrolateral thalamus were examined using the method of retrograde transport of horseradish peroxidase (HRP). 2. A thin, continuous slab of labeled neurons was found in the ventrolateral thalamus followingmultiple injections of HRP into the arm area of the motor cortex. The slab of labeled neurons was flanked, medially and laterally, by groups of unlabeled neurons. 3. The origin of ventrolateral thalamic input was more extensive than previously thought. Labeled neurons were found from A10.0 to A6.0 and occurred in three ventolateral thalamic subdivisions: ventralis lateralis pars oralis (VLo), ventralis lateralis pars caudalis (VLc), and ventralis posterior lateralis pars oralis (VPLo). For simplicity this region containing labeled neurons has been termed the ventrolateral thalamic (VL) arm area. 4. Injections of HRP into the somatic sensory cortex indicated that the thalamic regions which project to the somatic sensory cortex are separate from the VL arm area. 5. The distribution of labeled neurons following single injections of HRP into different regions of the motor cortex arm area indicated that the VL arm area is topographically organized, particularly its caudal part. Ventral regions of the VL arm area were labeled following HRP injections into motor cortex regions adjacent to the central sulcus where the representation of largely distal musculature is localized. Dorsal regions of the VL arm area were labeled following HRP injections into motor cortex regions more rostral to the central sulcus where the representation of more proximal musculature is localized. 6. A larger region of the VL arm area was labeled following HRP injections adjacent to the central sulcus than following the more rostral motor cortex injections. This suggests that, like the arm area of the motor cortex, more of the VL arm area is allotted to the representation of distal than proximal musculature. 7. Following very small cortical HRP injections, isolated labeled thalamic neurons were diffusely scattered throughout a 3-mm rostrocaudal extent of the VL arm area. In addition, a small focal cluster of labeled thalamic neurons was also seen. The labeled cluster was limited to 0.5 mm rostrocaudally and 300 mum in width. The focal distribution of labeled thalamic neurons suggests that aspects of a point to point organization may exist in the connection between VL and the motor cortex arm area.

A New Extrusion Plastometer

1944 ◽  
Vol 17 (3) ◽  
pp. 745-750
Author(s):  
H. A. Schultz ◽  
R. C. Bryant
Keyword(s):  
Laboratory Test ◽  
The Other ◽  
Central Portion ◽  
Tensile Stresses ◽  
Synthetic Rubber ◽  
Preliminary Work ◽  
Continuous Slab ◽  
Set Up

Abstract Early studies of the processing characteristics of synthetic rubber (GR-S) indicated that it would be desirable to have a laboratory test to determine whether satisfactory tread slabs could be produced from a given batch of tread stock by extrusion through a plate die. In the factory, the material is extruded as a continuous slab, flat on one side and shaped on the other. The extruding material is put under tension and carried away by a moving belt. Since the central portion of the slab, which will eventually become the tire tread, is thicker than the adjoining sidewall portions, it is extruded at a greater rate. Therefore, tensile stresses are set up in the sidewalls after the stock leaves the die. The material either flows to relieve these stresses or it tears. Preliminary work indicated that common methods of measuring plasticity were not adequate to measure or predict the tendency of certain stocks to tear in the sidewalls. Therefore, it was decided to develop a test which should reproduce the essential features of factory extrusion in miniature and under close control. This was accomplished in a new extrusion plastometer by the use of special dies and of a device to apply tension to the extruding sample.

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