Experimental Procedure for the In-Shear Adhesive Strength Evaluation Under High-Frequency Cyclic Loading

2022 ◽  
Author(s):  
O. G. Trapezon
Keyword(s):  
Cyclic Loading ◽  
Adhesive Strength ◽  
High Frequency ◽  
Experimental Procedure ◽  
Strength Evaluation

Fatigue resistance of copper fiber-base rolled porous materials in high-frequency cyclic loading

1991 ◽  
Vol 30 (10) ◽  
pp. 870-872
Author(s):  
A. V. Vdovichenko ◽  
V. A. Kuz'menko ◽  
Yu. F. Lugovskoi ◽  
V. A. Nazarenko
Keyword(s):  
Cyclic Loading ◽  
Porous Materials ◽  
Fatigue Resistance ◽  
High Frequency

Convenient Adhesive Strength Evaluation Method in Terms of the Intensity of Singular Stress Field

2018 ◽  
Vol 16 (01) ◽  
pp. 1850085 ◽  
Author(s):  
Nao-Aki Noda ◽  
Rong Li ◽  
Tatsujiro Miyazaki ◽  
Rei Takaki ◽  
Yoshikazu Sano
Keyword(s):  
Stress Field ◽  
Conventional Method ◽  
Adhesive Strength ◽  
Evaluation Method ◽  
Singular Stress ◽  
Strength Evaluation ◽  
Present Solution ◽  
Singular Stress Field

A convenient evaluation method is proposed for the debonding adhesive strength in terms of the intensity of singular stress field (ISSF) appearing at the end of interface. The same FEM mesh pattern is applied to unknown problems and reference problems. It is found that the ISSF is obtained accurately by focussing on the FEM stress at the adhesive corner. Then, the debonding condition can be expressed as a constant value of critical ISSF. The usefulness of the present solution is verified by comparing with the results of the conventional method.

The Behavior of Salem Limestone in Cyclic Loading

1974 ◽  
Vol 14 (01) ◽  
pp. 19-24 ◽  
Author(s):  
S.S. Peng ◽  
E.R. Podnieks ◽  
P.J. Cain
Keyword(s):  
Fatigue Life ◽  
Cyclic Loading ◽  
Material Properties ◽  
High Frequency ◽  
Low Frequency ◽  
Tensile Loading ◽  
Cyclic Stress ◽  
Time Dependent ◽  
Mean Stress ◽  
Frequency Range

Abstract Specimens of Salem limestone were loaded cyclically at a frequency of 2 cycles/sec in uniaxial cyclic compression, tension, and compression-tension. The number of cycles to failure, maximum deformation for each cycle, and load-deformation hysteresis loops were recorded. The fatigue life and fatigue limit values under cyclic compressive loading are comparable with those under cyclic tensile loading, whereas under cyclic compressive-tensile loading they are considerably lower. Introduction The study of rock behavior in cyclic loading has been relatively ignored in the past, even though certain problems in rock mechanics are closely related to cyclic loading. These problems include the effects of percussive drilling and the vibrations generated by blasting. An understanding of the mechanisms of fatigue failure in rock can be expected to help improve drilling efficiency and prevent vibration damage caused by blasting. Because of the lack of bask information on rock behavior under cyclic loading, the Federal Bureau of Mines, Twin Cities Mining Research Center began in 1968 an extensive program for studying cyclic loading effects. This program included the investigation of the behavior of rock loaded cyclically at different frequencies under varying test geometries, loading configurations, and environments. In the high-frequency range, sonic power transducers are being used to apply cyclic loading at a frequency of 10,000 Hz, and an electromagnetic shaker is being used at frequencies from 100 to 1,000 Hz. In the low-frequency range, cyclic loading of 2 to 10 Hz is applied by a closed-loop servocontrolled electrohydraulic testing machine. In each frequency range, experiments are conducted to provide the following information: fatigue limits, fatigue life, energy dissipation, temperature induced in the specimen, and the time history of load and deformation. This paper presents the first phase of be results obtained on specimens of Salem limestone loaded in the low-frequency range. The early findings on the high-frequency effects were reported separately. Recently, the effect of cyclic loading on rock behavior has been receiving more attention and considerable information is being generated. General Loading Concept in Cyclic Loading In conventional strength tests the monotonic loading program is specified by the loading rate and control mode. For cyclic loading, where the load is a periodic function of time, the problem is more complex. To evaluate such material properties as fatigue life, the load must be described systematically and concisely in terms of physically significant parameters. parameters. For a general case, one approach is to divide the cyclic stress into time-independent and time-dependent components. The time-independent component (or mean stress) is the time average of the stress. A cyclic stress with an amplitude A and zero mean can be superimposed on this loading. For the usual case of cyclic loading with steady loading conditions, the stress can be described as follows.(1)= + (t), where f(t) is a periodic function of time, t, and can be represented by a sine or sawtooth wave. Other ways of describing the stress are available such as using the maximum and minimum stresses, which are related to the mean and amplitude:(2)max = . and(3)min = . The key issue is to describe the loading in terms that will correlate with the material properties of interest. The use of amplitude and mean stress to describe cyclic loading separates the time-dependent bona the time-independent portion of the stress because the effect of each portion of the loading should be investigated separately. In analyzing the effect of cyclic loading on rock, another significant factor is the large difference between the tensile strength and the compressive strength. P. 19

Shear Modulus of Soft Marine Clays

1989 ◽  
Vol 111 (4) ◽  
pp. 265-272 ◽  
Author(s):  
S. Pamukcu
Keyword(s):  
Cyclic Loading ◽  
Shear Modulus ◽  
High Frequency ◽  
Dynamic Testing ◽  
Strain Range ◽  
Ocean Bottom ◽  
Static Data ◽  
Measured Strain ◽  
Cyclic Degradation ◽  
Marine Clays

Instabilities occur frequently in ocean-bottom sediments where the deposition is faster than the consolidation of the material. Cyclic loading of waves contribute to the existing pore pressures within the sediment reducing the effective stresses. The sediment can lose strength and stability and flow in gullies of depth up to 30 m, on slopes less than 0.5 deg. One theory and some related experiments indicate that, depending on the depositional conditions and state of stress, the failure mechanism for such soft saturated marine clays may not necessarily require large straining of the material. Laboratory determination of low-strain shear behavior or shear modulus of soft marine clays can be complicated if high-frequency dynamic testing methods are utilized. Cyclic loading can promote fast degradation of moduli for these soils even at low strain amplitudes. A monotonic torsional shear device, namely a triaxial vane device, was equipped with a computer-aided data acquisition system to detect low-strain shear deformations under quasi-static loading conditions. The average range of electronically measured strain range was 10−4 to 1 percent, which was compatible with that of a high-frequency, low-strain dynamic testing method, namely, resonant column. Comparison of the dynamic and static moduli reduction curves of artificially prepared soft kaolinite specimens demonstrated the cyclic degradation effects on such clays. The relatively continuous, high-resolution low-strain static data indicated further gain in understanding of low-strain nonlinearity and yielding behavior of soft marine clays.

scholarly journals Fatigue Properties of Nodular Cast Iron at Low Frequency Cyclic Loading

2017 ◽  
Vol 62 (4) ◽  
pp. 2205-2210 ◽  
Author(s):  
A. Vaško
Keyword(s):  
Cast Iron ◽  
Cyclic Loading ◽  
High Frequency ◽  
Stress Ratio ◽  
Low Frequency ◽  
Nodular Cast Iron ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Charge Composition ◽  
Cast Irons

Abstract Three melts of ferrite-pearlitic nodular cast iron with different charge composition were used for fatigue tests. Wöhler fatigue curves and fatigue strength were obtained, and microstructure and fracture surfaces were investigated. The aim of the paper is to determine the influence of charge composition on microstructure, mechanical and fatigue properties of synthetic nodular cast irons and their micromechanisms of failure. Fatigue tests were realised at low frequency sinusoidal cyclic push-pull loading (stress ratio R = −1) at ambient temperature (T = 20 ±5°C). They were carried out with using the fatigue experimental machine Zwick/Roell Amsler 150HFP 5100 at frequency f ≈ 120 Hz. The results of fatigue tests at low frequency cyclic loading are compared with fatigue properties at high frequency cyclic loading.

Unfavourable short-term outcomes of a poly-L/D-lactide scaffold for thumb trapeziometacarpal arthroplasty

2015 ◽  
Vol 41 (3) ◽  
pp. 328-334 ◽  
Author(s):  
S. Mattila ◽  
E. Waris
Keyword(s):  
Foreign Body ◽  
Cyclic Loading ◽  
Pain Relief ◽  
High Frequency ◽  
Recent Attempt ◽  
Short Term ◽  
Trapeziometacarpal Osteoarthritis ◽  
Foreign Body Reactions ◽  
Tissue Reactions

The bioabsorbable poly-L-D-lactide joint scaffold arthroplasty is a recent attempt in the reconstruction of small joints in rheumatoid patients. In this study, we analysed the 1-year clinical, functional and radiologic results of partial trapeziectomy with the poly-L-D-lactide (96/4) joint scaffold in 23 patients with isolated trapeziometacarpal osteoarthritis. The results showed that the procedure provided pain relief and improvement in overall function according to the Quick Disabilities of the Arm, Shoulder and Hand score in most patients. However, radiographs demonstrated a high frequency of osteolysis around the implant. Seven patients developed clinically manifested foreign-body reactions 6 months to 1 year after surgery. The reason for the unexpected tissue reactions may relate to excessive mechanical cyclic loading of the implant. The outcomes of this implant in our patients have not been sufficiently beneficial and we have discontinued use of this implant in isolated trapeziometacarpal osteoarthritis.

Sign in / Sign up

Export Citation Format

Share Document