Experimental Investigation on Residual Strength of Plain Concrete under Fatigue Biaxial Compression with Constant Confined Stress

2011 ◽  
Vol 261-263 ◽  
pp. 581-585
Author(s):  
X.H. Meng ◽  
W.W. Wang ◽  
J.H. Zhou ◽  
Yu Pu Song

A model of attenuation of residual strength with number of cycles has been founded .In this model the constant confined stress and maximum stress of fatigue loading are both considered. 55 specimens of plain concrete are tested under biaxial compressive fatigue loading with constant confined stress. Based on the data of experiment, the coefficients of the model are determined. The residual strength attenuating curves are shown in the paper. The model can be used to predict the residual life of specimen under biaxial compressive loading with constant confined stress. The results of prediction show that the suggested method is better than the Miner rule.

2012 ◽  
Vol 430-432 ◽  
pp. 1843-1846
Author(s):  
Xian Hong Meng ◽  
Yu Xian Zhang ◽  
Jing Hai Zhou

A model of attenuation of residual strength with number of cycles has been founded .In this model the constant confined stress and maximum stress of fatigue loading are both considered. Based on the data of experiment, the coefficients of the model are determined. The model can be used to predict the residual life of specimen under biaxial compressive loading with constant confined stress.


Energies ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 251
Author(s):  
Piotr Osiński ◽  
Grzegorz Chruścielski ◽  
Leszek Korusiewicz

This article presents theoretical and experimental calculations of the minimum thickness of a compensation lip used in external gear pumps. Pumps of this type are innovative technical solutions in which circumferential backlash (clearance) compensation is used to improve their volumetric and overall efficiency. However, constructing a prototype of such a pump requires long-lasting research, and the compensation lip is its key object, due to the fact that it is an element influenced by a notch and that it operates in unfavorable conditions of strong fatigue stresses. The theoretical calculations presented in this article are based on identifying maximum stress values in a fatigue cycle and on implementing the stress failure condition and the conditions related to the required value of the fatigue safety factor. The experimental research focuses on static bending tests of the lips as well as on the fatigue loading of the lips in series of tests at increasing stress values until lip failure due to fatigue. The tests allowed the minimum lip thickness to be found for the assumed number of fatigue cycles, which is 2.5 times the number of cycles used in wear margin tests.


1994 ◽  
Vol 27 (9) ◽  
pp. 505-509 ◽  
Author(s):  
Krzystof Dyduch ◽  
Maria Szerszeń ◽  
Jean-François Destrebecq

2021 ◽  
pp. 002199832199842
Author(s):  
Bin Yang ◽  
Kunkun Fu ◽  
Yan Li

In this paper, a finite element model (FEM) was developed to investigate failure mechanism and compression after impact (CAI) strength of woven carbon fibre reinforced polymer (CFRP) after low-velocity impact (LVI) subjected to biaxial compressive loading. A built-in VUMAT user-defined material subroutine was adopted to take into account the in-plane damage and intralaminar delamination under LVI loading and in-plane compression. The LVI response, failure pattern, and residual mechanical properties under uniaxial compression were compared to the available experimental data to verify the numerical model. The damage initiation, subsequent evolution, final failure modes, and residual strength of the composite laminates with LVI damages subjected to biaxial compressive loading are presented by numerical methods, and the effects of impact energy and impactor diameter on the residual strength of the laminates are discussed.


2019 ◽  
Vol 8 (2S11) ◽  
pp. 2934-2938

The researched work quite essentially deals with the resoluteness of the safety and structural integrity of the centrifugal impeller in withstanding the forces impacted on the targeted materials Ti-6Al-4V and Au2gn. In order to counteract the effects prevalent as a result of profound instabilities such as surging, stalling and choking, the materials were subjected to an intense comparative study, undertaken with respect to primary parameters such as good strength yield, in addition to dispensing a rotational speed of 20000 rpm. The preliminary solid modeling was executed using CATIAV5. Structural Analysis is carried out using ANSYS software in order to establish their strengths together with the location of maximum stress and strain. 2D FEM simulation was done on the impeller. Furthermore the number of cycles to failure was computed using the best amongst the known strain – based life estimation methods. From the modal analysis the ubiquitous critical mode shape along with the frequency at which the maximum relative displacement occurs were obtained. Finally, Ti-6Al-4V was affirmed to be better than Au2gn.


2010 ◽  
Vol 150-151 ◽  
pp. 1379-1382 ◽  
Author(s):  
Hong Bing Zhu ◽  
Xiu Li

To investigate the residual strength degradation of recycled aggregate concrete under fatigue loading, experiments were conducted to determine the functional relation between residual strength and the number of cycles. Fifty 100mm ×100mm ×100mm specimens of recycled aggregate concrete were tested under uniaxial compressive fatigue loading. Based on probability distribution of the residual strength of concrete under fatigue loading, the P-R-N curves are obtained based on test data, the empirical expressions of the residual strength corresponding to the number of cycles were obtained. The curves can be used to predict the residual strength with reliability.


Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4622
Author(s):  
Kevin Paolo V. Robles ◽  
Jurng-Jae Yee ◽  
Seong-Hoon Kee

The main objectives of this study are to evaluate the effect of geometrical constraints of plain concrete and reinforced concrete slabs on the Wenner four-point concrete electrical resistivity (ER) test through numerical and experimental investigation and to propose measurement recommendations for laboratory and field specimens. First, a series of numerical simulations was performed using a 3D finite element model to investigate the effects of geometrical constraints (the dimension of concrete slabs, the electrode spacing and configuration, and the distance of the electrode to the edges of concrete slabs) on ER measurements of concrete. Next, a reinforced concrete slab specimen (1500 mm (width) by 1500 mm (length) by 300 mm (thickness)) was used for experimental investigation and validation of the numerical simulation results. Based on the analytical and experimental results, it is concluded that measured ER values of regularly shaped concrete elements are strongly dependent on the distance-to-spacing ratio of ER probes (i.e., distance of the electrode in ER probes to the edges and/or the bottom of the concrete slabs normalized by the electrode spacing). For the plain concrete, it is inferred that the thickness of the concrete member should be at least three times the electrode spacing. In addition, the distance should be more than twice the electrode spacing to make the edge effect almost negligible. It is observed that the findings from the plain concrete are also valid for the reinforced concrete. However, for the reinforced concrete, the ER values are also affected by the presence of reinforcing steel and saturation of concrete, which could cause disruptions in ER measurements


1967 ◽  
Vol 182 (1) ◽  
pp. 657-684 ◽  
Author(s):  
J. Spence ◽  
W. B. Carlson

Nozzles in cylindrical vessels have been of special interest to designers for some time and have offered a field of activity for many research workers. This paper presents some static and fatigue tests on five designs of full size pressure vessel nozzles manufactured in two materials. Supporting and other published work is reviewed showing that on the basis of the same maximum stress mild steel vessels give the same fatigue life as low alloy vessels. When compared on the basis of current codes it is shown that mild steel vessels may have five to ten times the fatigue life of low alloy vessels unless special precautions are taken.


1959 ◽  
Vol 10 (4) ◽  
pp. 326-344 ◽  
Author(s):  
H. T. Jessop ◽  
C. Snell ◽  
I. M. Allison

The “frozen stress” techniques of photoelasticity can give a complete knowledge of the stress, system in a solid body, but the examination of the stresses requires more time and care than in corresponding flat plate tests. In tests on tubes with transverse circular holes, sponsored by The Royal Aeronautical Society, all practicable geometrical shapes are examined and the maximum stress is measured in tension, bending and torsion. The results are comprehensive and show the inadequacy of previous results. In all cases the maximum stress occurs inside the bore of the hole. The accuracy of all the graphs of stress concentration factors is better than five per cent.


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