Size effects on nominal tensile strength of concrete structures: multifractality of material ligaments and dimensional transition from order to disorder

1995 ◽  
Vol 28 (6) ◽  
pp. 311-317 ◽  
Author(s):  
Alberto Carpinteri ◽  
Bernardino Chiaia ◽  
Giuseppe Ferro
2017 ◽  
Vol 85 (2) ◽  
Author(s):  
Jia-Liang Le ◽  
Jan Eliáš ◽  
Anna Gorgogianni ◽  
Joshua Vievering ◽  
Josef Květoň

This paper investigates the effect of strain rate on the scaling behavior of dynamic tensile strength of quasibrittle structures. The theoretical framework is anchored by a rate-dependent finite weakest link model. The model involves a rate-dependent length scale, which captures the transition from localized damage to diffused damage with an increasing strain rate. As a result, the model predicts a rate- and size-dependent probability distribution function of the nominal tensile strength. The transitional behavior of the strength distribution directly leads to the rate and size effects on the mean and standard deviation of the tensile strength. The model is verified by a series of stochastic discrete element simulations of dynamic fracture of aluminum nitride specimens. The simulations involve a set of geometrically similar specimens of various sizes subjected to a number of different strain rates. Both random microstructure geometry and fracture properties are considered in these simulations. The simulated damage pattern indicates that an increase in the strain rate results in a more diffusive cracking pattern, which supports the theoretical formulation. The simulated rate and size effects on the mean and standard deviation of the nominal tensile strength agree well with the predictions by the rate-dependent finite weakest link model.


Alloy Digest ◽  
1981 ◽  
Vol 30 (8) ◽  

Abstract CENTRI-CAST GRAY IRON 50 is a centrifugally cast gray iron with a nominal tensile strength of 50,000 psi. It is cast in the form of tubing which has a wide range of uses in applications where size and shape are of paramount importance and freedom from pattern cost is an important consideration. Among its many applications are farm machinery, seals, bushings, machine tools and general machinery uses. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, tensile properties, and compressive and shear strength as well as fatigue. It also includes information on casting, heat treating, machining, and surface treatment. Filing Code: CI-51. Producer or source: Federal Bronze Products Inc..


Alloy Digest ◽  
1979 ◽  
Vol 28 (9) ◽  

Abstract CENTRI-CAST GRAY IRON 55 is a centrifugally cast gray iron with a nominal tensile strength of 55,000 psi. It is produced in the form of tubing which has a wide range of uses in applications where size and shape are of paramount importance and freedom from pattern cost is an important consideration. Typical applications are seals, bushings, farm machinery, casings and general machinery uses. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, tensile properties, and compressive and shear strength as well as fatigue. It also includes information on casting, heat treating, machining, and surface treatment. Filing Code: CI-48. Producer or source: Federal Bronze Products Inc..


2018 ◽  
Vol 760 ◽  
pp. 213-218
Author(s):  
František Girgle ◽  
Lenka Bodnárová ◽  
Ondřej Januš ◽  
Vojtěch Kostiha

The article deals with the current problem of determining long-term reliability of non-metallic reinforcement in concrete structures. The alkaline environment of concrete with a pH higher than 12.0 affects the glass fibres degradative, whereas this degradation presents by reduction of their mechanical characteristics, resulting in a decrease in the tensile strength of the whole composite. The article summarizes the results of the ongoing experimental program so far, which aims to quantify this influence.


2011 ◽  
Vol 418-420 ◽  
pp. 307-312
Author(s):  
Shi Yong Jiang ◽  
Bing Hong Li ◽  
Qian Hua Shi ◽  
Xian Qi Hu

The replacement of steel stirrups with FRP stirrups in concrete structures can significantly improve the durability under severe environmental conditions, increase the service life of the structure. In some cases where the application of traditional concrete structures is restricted, such as structures that require the environment without magnetic and electric interferences, the best way is to use nonmetallic materials. Considering the unique properties compared with traditional reinforcements, FRP reinforcements is very suitable in such cases. This paper discussed the behavior of FRP stirrups used as shear reinforcement for concrete structures, continuous FRP rectangular spirals, a type of FRP stirrups, was used in the experimental investigation. Inspired by the test method suggested by ACI Committee 440, L shape specimen and U shape specimen are designed to test the tensile strength of continuous FRP rectangular spirals. Through the analysis of test results, it is indicated that the strength of the bent portion of FRP spirals is significantly lower than that of the straight portion, and the strength of FRP spirals would increase as the concrete strength or the embedment length of the bent portion increased. The loading mechanism of continuous FRP rectangular spirals embedded in concrete beams can be better represented by U shape specimen compared with L shape specimens, it is suggested by the author that the U shape specimen can be use when the dimension of FRP stirrups or spirals does not meet the requirements of ACI Committee 440 test method.


2016 ◽  
Vol 29 (7) ◽  
pp. 759-771 ◽  
Author(s):  
Peyman Pouresmaeel-Selkjani ◽  
Mohsen Jahanshahi ◽  
Majid Peyravi

The effect of three different diphenols including 1,1′-thiobis(2-naphthol) (TBN), 2,2′-thiobis(4-methyl phenol) (TBMP) and curcumin (CUR) used in the preparation of sulfonated poly(ether sulfide sulfone) (SPESS) on the mechanical, thermal, and morphological properties of polysulfone (PSf) membranes was studied. In this regard, the morphological characteristics of the nanoporous membranes were explored by developed image analyzer program. Based on the obtained results, PSf membrane modified by SPESS-TBN copolymer showed the best nominal tensile strength in comparison to the other samples with the value of 206 MPa. The optimum real tensile strength with the value of 322 MPa was observed for SPESS-TBMP membrane. It was found that the addition of SPESS, improved the mechanical and thermal properties as well as the performance of membranes. Inspections of scanning electron microscopic images for evaluation of the void properties of membranes revealed that there were 42.3, 8.76, 41.45 and 15.92% of void contents within the structures of neat PSf membrane, SPESS-CUR, SPESS-TBMP and SPESS-TBN, respectively. Moreover, some conceptual relations between morphological and mechanical properties were presented. Finally, the effect of the membrane chemical structure on the mechanical, thermal, and morphological properties was discussed in this study.


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