Shear response and failure mode of masonry triplets subjected to monotonic and cyclic loading

The aim of this study is to evaluate the microstructures, tensile lap shear strength, and fatigue resistance of 6022-T43 aluminum alloy joints welded via a solid-state welding technique–ultrasonic spot welding (USW)–at different energy levels. An ultra-fine necklace-like equiaxed grain structure is observed along the weld line due to the occurrence of dynamic crystallization, with smaller grain sizes at lower levels of welding energy. The tensile lap shear strength, failure energy, and critical stress intensity of the welded joints first increase, reach their maximum values, and then decrease with increasing welding energy. The tensile lap shear failure mode changes from interfacial fracture at lower energy levels, to nugget pull-out at intermediate optimal energy levels, and to transverse through-thickness (TTT) crack growth at higher energy levels. The fatigue life is longer for the joints welded at an energy of 1400 J than 2000 J at higher cyclic loading levels. The fatigue failure mode changes from nugget pull-out to TTT crack growth with decreasing cyclic loading for the joints welded at 1400 J, while TTT crack growth mode remains at all cyclic loading levels for the joints welded at 2000 J. Fatigue crack basically initiates from the nugget edge, and propagates with “river-flow” patterns and characteristic fatigue striations. Keywords: aluminum alloy; ultrasonic spot welding; EBSD; microstructure; tensile strength; fatigue

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Shear Response under Reversed Cyclic Loading

ACI Structural Journal ◽

10.14359/51689033 ◽

2016 ◽

Vol 113 (6) ◽

Cited By ~ 3

Author(s):

David M. Ruggiero ◽

Evan C. Bentz ◽

G. M. Calvi ◽

Michael P. Collins

Keyword(s):

Cyclic Loading ◽

Reversed Cyclic Loading ◽

Shear Response ◽

Reversed Cyclic

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The Fatigue Strength and Failure Mode of Coal Sample Subjected to Cyclic Loading

Geotechnical and Geological Engineering ◽

10.1007/s10706-018-0725-2 ◽

2018 ◽

Vol 37 (3) ◽

pp. 2255-2266 ◽

Cited By ~ 2

Author(s):

Jiakun Lv ◽

Yongjie Yang ◽

Shan Ning ◽

Huiqiang Duan

Keyword(s):

Fatigue Strength ◽

Cyclic Loading ◽

Failure Mode ◽

Coal Sample

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Failure Mode and Failure Strengths for Wall Thinning Straight Pipes and Elbows Subjected to Seismic Loading

Journal of Pressure Vessel Technology ◽

10.1115/1.2826425 ◽

2008 ◽

Vol 130 (1) ◽

Cited By ~ 16

Author(s):

Kunio Hasegawa ◽

Katsumasa Miyazaki ◽

Izumi Nakamura

Keyword(s):

Cyclic Loading ◽

Crack Initiation ◽

Failure Mode ◽

Seismic Event ◽

Low Cycle Fatigue ◽

Seismic Loading ◽

Fatigue Curve ◽

Wall Thinning ◽

Piping Systems ◽

Asme Code

It is important to assess the failure strengths for pipes with wall thinning to maintain the integrity of the piping systems and to make codification of allowable wall thinning. Full-scale fracture experiments on cyclic loading under constant internal pressure were performed for 4in. diameter straight pipes and 8in. diameter elbow pipes at ambient temperature. The experiments were low cycle fatigue under displacement controlled conditions. It is shown that a dominant failure mode under cyclic loading for straight pipes and elbows is crack initiation∕growth accompanying swelling by ratchet or buckling with crack initiation. When the thinning depth is deep, the failure mode is burst and crack growth with ratchet swelling. In addition, failure strengths were compared with the design fatigue curve of the ASME Code Sec. III. It is shown that pipes with wall thinning less than 50% of wall thickness have sufficient margins against a seismic event of the safety shutdown earthquake.

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Effects of Strain Rate on Reinforced Concrete Beam

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.243-249.4033 ◽

2011 ◽

Vol 243-249 ◽

pp. 4033-4036 ◽

Cited By ~ 4

Author(s):

Min Li ◽

Hong Nan Li

Keyword(s):

Reinforced Concrete ◽

Cyclic Loading ◽

Strain Rate ◽

Failure Mode ◽

Loading Rate ◽

Concrete Beams ◽

Reinforced Concrete Beams ◽

Strain Rate Effects ◽

Shear Span ◽

Rate Effects

The strain-rate effects of reinforced concrete beams are studied in this paper. Considering the strain-rate effects of structural material, dynamic responses of reinforced concrete beams subjected to monotonic loading and cyclic loading at different loading rates that might be experienced during earthquakes are simulated using the nonlinear finite element program ABAQUS. The influences of loading rate on loading capability and failure mode of reinforced concrete beams are investigated. The results show that as the loading rate increases, the loading capability increases, the increment is associated with the shear span ratio and loading mode. The increment at cyclic loading is smaller than that at monotonic loading; as the shear span ratio changes, the failure mode changes, the increment changes; the failure mode has nothing to do with the loading rate.

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Shear Response of Wet Weak Carbonate Rock/Grout Interfaces Under Cyclic Loading

Rock Mechanics and Rock Engineering ◽

10.1007/s00603-021-02406-1 ◽

2021 ◽

Author(s):

Eleni Stavropoulou ◽

Christophe Dano ◽

Marc Boulon

Keyword(s):

Cyclic Loading ◽

Carbonate Rock ◽

Failure Modes ◽

Mechanical Response ◽

Offshore Wind ◽

Shear Behaviour ◽

Clear Correlation ◽

Engineering Practice ◽

Shear Tests ◽

Shear Response

AbstractThe development and construction of offshore wind farms requires the correct estimation of the friction that can be mobilised at the rock/grout interface. In conventional studies, the shear behaviour of a joint is usually investigated with laboratory tests under constant normal load/stress (CNL), however, in engineering practice, direct shear testing under constant normal stiffness (CNS) has been proved to be more realistic in the assessment of the development of the side shear resistance in rock grouted pile design. In this work, an extensive experimental campaign on the shear response of a weak carbonate rock (limestone) interface with grout is presented, in the frame of offshore wind turbines. First, basic mechanical testing is performed on the two interface materials in order to evaluate their mechanical properties. The output of these tests reveals not only the contrasting properties of the two interacting materials, but also the decreased response of the limestone in the presence of water. A series of monotonic shear tests (both under CNL and CNS conditions) on wet rough limestone/grout interfaces reveal the high impact of adhesion between the two materials to the mechanical response. Based on the monotonic results, a number of CNS shear tests under cyclic loading takes place, where different failure modes are observed dilatant and contractant response. The variability of the failure mode is strongly related not only to the adhesion created with the cast grout, but also to the limestone’s micro-structural heterogeneity that manifests already after consolidation. The post-shear morphological state of the interface is analysed, while the variability of the failure surface and the presence of water gouge creation do not allow a clear correlation of the morphologfy to the mechanical response. Overall, the response of this type of weak rock interface where the properties of the grout are significantly higher, is governed by the behaviour of the rock.

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Numerical Study on the Mechanical Properties of Transmission Tower K-Joints under Cyclic Loading

Shock and Vibration ◽

10.1155/2021/7403365 ◽

2021 ◽

Vol 2021 ◽

pp. 1-11

Author(s):

Jia-xiang Li ◽

Chao Zhang ◽

Shu-hong Wang ◽

Sheng-qiang Yin

Keyword(s):

Mechanical Properties ◽

Cyclic Loading ◽

Failure Mode ◽

Numerical Study ◽

Hysteretic Behavior ◽

Hysteresis Curve ◽

Transmission Tower ◽

Vibration Load ◽

Hysteretic Characteristics ◽

The Moment

During the vibration of a transmission tower, the joints will be subjected to a reciprocating load. To obtain the accurate state of the transmission tower under the load, the mechanical properties of the joints under the vibration load must be considered. In this paper, the mechanical properties of typical K-joints in transmission tower structures are studied by numerical simulation. The failure mode of the K-joint under cyclic loading is also analyzed. The mechanical properties of the K-joint are discussed from the aspects of hysteretic characteristics, stiffness degradation, energy dissipation capacity, and ductility evaluation, and the influencing factors are discussed. The results show that the failure mode of the K-joint is related to the bolt grade and steel strength. When analyzing K-joints, the moment-rotation hysteresis curve should be combined with the realistic parameters of joints to consider the hysteretic behavior of the K-joint. The results provide a theoretical reference for the accurate modeling of transmission towers.

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Experimental Study on Precast Concrete Shear Walls with Different Hollow Slabs

The Open Civil Engineering Journal ◽

10.2174/1874149501408010166 ◽

2014 ◽

Vol 8 (1) ◽

pp. 166-171 ◽

Cited By ~ 1

Author(s):

Qinyan Zhao ◽

Zhongyong Zhang ◽

Jiliang Liu ◽

Mingjin Chu

Keyword(s):

Experimental Study ◽

Cyclic Loading ◽

Failure Mode ◽

Shear Failure ◽

Precast Concrete ◽

Shear Walls ◽

Test Results ◽

Mechanical Behaviors ◽

Low Cyclic Loading

To study mechanical behaviors of shear walls built with precast two-way hollow slabs, two shear walls with different details of hollow slabs were quasi-statically tested under low cyclic loading. The failure mode was analyzed, which vertical macro-cracks appeared on walls due to the details of hollow slabs. Brittle shear failure can be avoided in terms of the failure behaviors evolved from integral wall to the combination of wall and columns. Test results also show that that dimension of transverse holes can affect compressive capacity of the walls when it is larger than that of longitudinal holes in the hollow slab.

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Anchored Transosseous-Equivalent Versus Anchorless Transosseous Rotator Cuff Repair: A Biomechanical Analysis in a Cadaveric Model

The American Journal of Sports Medicine ◽

10.1177/0363546517706136 ◽

2017 ◽

Vol 45 (10) ◽

pp. 2364-2371 ◽

Cited By ~ 14

Author(s):

Kelly G. Kilcoyne ◽

Stanley G. Guillaume ◽

Catherine V. Hannan ◽

Evan R. Langdale ◽

Stephen M. Belkoff ◽

...

Keyword(s):

Cyclic Loading ◽

Rotator Cuff ◽

Failure Mode ◽

Failure Load ◽

Tendon Tear ◽

Modes Of Failure ◽

Load To Failure ◽

Cadaveric Model

Background: The original approach for the repair of torn rotator cuffs involved an open technique with sutures passing through the greater tuberosity and tendon. The development of suture anchors allowed for an all-arthroscopic approach with anchor configurations attempting to re-create a transosseous fixation pattern. Presently, an arthroscopic approach can be combined with a transosseous suture configuration without using anchors. Purpose: To evaluate cyclic loading, ultimate load to failure, and the failure mechanisms of transosseous-equivalent (TOE) repair with anchors and anchorless transosseous (AT) repair of rotator cuff tears. Study Design: Controlled laboratory study. Methods: Supraspinatus tears (25 mm) were created in 20 fresh-frozen, human cadaveric shoulders, which were randomized to TOE or AT repair (10 in each group, paired experimental design). Biomechanical testing was performed with an initial preload, cyclic loading, and load to failure. Optical markers were used to monitor gap formation in 3 planes, and the failure mode was recorded. Paired t tests were used to make comparisons of biomechanical parameters between the groups. Multinomial logistic regression was used to compare failure modes between the groups. Significance was set to .05. Results: The TOE group had a significantly higher mean (±SD) ultimate failure load (578.5 ± 123.8 N) than the AT group (468.7 ± 150.9 N) ( P = .034). The TOE group also had a significantly less mean first-cycle excursion (2.97 ± 1.97 mm) than the AT group (4.70 ± 2.04 mm) ( P = .046). There were no significant differences between the groups in cyclic elongation or linear stiffness during cyclic loading. Primary modes of failure were a type 2 tendon tear with medial tendon disruption in the TOE group (7/10) and a type 1 tendon tear with lateral tendon disruption in the AT group (6/10). Conclusion: TOE repair resulted in a significantly higher mean failure load compared with AT repair in a cadaveric model. The most common modes of failure were a type 2 tendon tear in the TOE group and a type 1 tendon tear in the AT group. Clinical Relevance: A higher mean failure load in TOE versus AT constructs may come at the cost of a less favorable failure mode adjacent to medial anchors at the musculotendinous junction, potentially making revision difficult.

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Failure Mode and Failure Strengths for Wall Thinning Straight Pipes and Elbows Subjected to Cyclic Loading

Volume 6: Materials and Fabrication ◽

10.1115/pvp2005-71358 ◽

2005 ◽

Cited By ~ 2

Author(s):

Kunio Hasegawa ◽

Katsumasa Miyazaki ◽

Izumi Nakamura

Keyword(s):

Cyclic Loading ◽

Crack Initiation ◽

Internal Pressure ◽

Failure Mode ◽

Seismic Event ◽

Low Cycle Fatigue ◽

Cycle Fatigue ◽

Wall Thinning ◽

Piping Systems ◽

Large Burst

It is important to assess the failure strengths for pipes with wall thinning to maintain the integrity of the piping systems and to make codification of allowable wall thinning. Full-scale fracture experiments on cyclic loading under constant internal pressure were performed for 4-inch diameter straight pipes and 8-inch diameter elbow pipes at ambient temperature. The experiments were low cycle fatigue under displacement controlled condition. It is shown that dominant failure mode under cyclic loading for straight pipes and elbows is crack initiation/growth accompanying swelling by ratchet or buckling with crack initiation. When the thinning depth is large, burst occurs after swelling. In addition, it is shown that pipes with wall thinning less than 50% of wall thickness have sufficient margins against seismic event of the safety shut down earthquake (SSE).

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