Elastic Property Determination of WC Spheres and Estimation of Compressive Loads and Impact Velocities that Initiate their Yielding and Cracking

Author(s):  
A. A. Wereszczak
1940 ◽  
Vol 13 (2) ◽  
pp. 290-301 ◽  
Author(s):  
Lawrence A. Wood ◽  
Norman Bekkedahl ◽  
Chauncey G. Peters

Abstract The interferometer method for the measurement of small dimensional changes is adapted here to measurements on soft rubber. A detailed dsecription is given concerning the preparation of specimens, the apparatus, the procedure and the calculations necessary for the application of this method. Particular emphasis is placed on the measurement of thermal expansivity and the dimensional changes involved in transitions between the different forms of rubber. The lower limit of temperature is set only by the refrigerating liquid, temperatures as low as −185° C. being utilized. The upper limit of temperature is set only by the rubber itself. Results obtained in a study of the expansivity and transitions of “stark” (frozen) rubber are given as an illustration of the application of the method. Other possible applications are the measurement of the swelling of rubber by vapors and the determination of stress-strain relations under compressive loads. The chief limitation of the application of this method to rubber arises from the plastic flow of unvulcanized rubber at elevated temperatures. The method also possesses the inconvenience of requiring continuous observation. Compared with alternative methods of measuring small dimensional changes, the method possesses advantages arising from its high sensitivity, from the small size of the specimens required, from the ease of obtaining temperature equilibrium, from the absence of a confining liquid and from the simplicity of the calculations.


Author(s):  
Caio Cardoso Scipião ◽  
Alfran Sampaio Moura

Foundations projects must present security measures concerning the structural element and soil-structure system failure and acceptable displacements. In buildings it is very common to have foundations which are only subjected to compressive loads, however, in many of them, the foundations are submitted to uplifting forces, thus it is also necessary to verify the safety conditions regarding uplift capacity. In this context, this article evaluates the applicability of specific and non-specific methods for estimating the uplift bearing capacity of continuous flight auger piles in granular soils. In addition to that, a method was developed in order to estimate the ultimate uplift capacity of these pile types. In order to so, this research was based on 97 Standard Penetration Tests (SPT), and 12 continuous flight auger piles in granular soils subjected to the uplift forces. Among the evaluated literature methods, the specific method that presented the best agreement was Meyerhof and Adams (1968), and the non-specific one was Meyerhof (1953), both with approximately 65% higher values, in average, than the reference values and with great scatter. On the other hand, the developed method presented good agreement and lower scatter, establishing an alternative for the determination of uplift bearing capacity of continuous flight auger piles in granular soils.


2003 ◽  
Vol 44 (1) ◽  
pp. 94-103 ◽  
Author(s):  
Hisanori Tanimoto ◽  
Seiji Sakai ◽  
Eiji Kita ◽  
Hiroshi Mizubayashi

1993 ◽  
Vol 20 (6) ◽  
pp. 895-909 ◽  
Author(s):  
Murray C. Temple ◽  
Ghada Elmahdy

An examination of the requirements for the design of built-up compression members in the North American and European standards and specifications reveals a great variation in the allowable maximum slenderness ratio for an individual main member, and also in the determination of an equivalent slenderness ratio. The requirements of the Canadian standard with regard to the determination of the maximum allowable slenderness ratio of a main member between points of connection can be a bit confusing.This research involved a study of model built-up members that buckled about an axis perpendicular to the plane of the connectors. Twenty-four tests were conducted on model built-up members. The theoretical analysis consisted of a finite element analysis of the model built-up struts. In addition, an equivalent slenderness ratio was calculated by several methods. These equivalent slenderness ratios were then used in conjunction with the requirements of the Canadian standard to calculate a compressive resistance, which was compared with the experimental failure load.From this research on built-up members that buckle about an axis perpendicular to the plane of the connectors it was found that at least two connectors should be used, that the slenderness ratio of the main member between points of connection has a significant effect on the compressive resistance, and that Timoshenko's equivalent slenderness ratio when used in conjunction with the Canadian standard gives results that are in the best agreement with the experimental results. Key words: battens, built-up members, compressive loads, connectors, equivalent slenderness ratio.


2019 ◽  
Vol 35 (6) ◽  
pp. 1210-1216 ◽  
Author(s):  
Wei He ◽  
Meidong Han ◽  
Shibin Wang ◽  
Philippe Goudeau ◽  
Eric Le Bourhis ◽  
...  

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