Potential Loss in Prestressing Tendon Forces under Long-Term Service Conditions: Cross-Laminated Timber Shear Wall Applications

AbstractIn this study, the lateral resistances of mass timber shear walls were investigated for seismic design. The lateral resistances were predicted by kinematic models with mechanical properties of connectors, and compared with experimental data. Four out of 7 shear wall specimens consisted of a single Ply-lam panel and withdrawal-type connectors. Three out of 7 shear wall specimens consisted of two panels made by dividing a single panel in half. The divided panels were connected by 2 or 4 connectors like a single panel before being divided. The applied vertical load was 0, 24, or 120 kN, and the number of connectors for connecting the Ply-lam wall-to-floor was 2 or 4. As a result, the tested data were 6.3 to 52.7% higher than the predicted value by kinematic models, and it means that the lateral resistance can be designed by the behavior of the connector, and the prediction will be safe. The effects of wall-to-wall connectors, wall-to-floor connectors and vertical loads on the shear wall were analyzed with the experimental data.

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Long-term behavior of cracked fiber reinforced concrete under service conditions

Construction and Building Materials ◽

10.1016/j.conbuildmat.2018.10.230 ◽

2019 ◽

Vol 196 ◽

pp. 649-658 ◽

Cited By ~ 5

Author(s):

D.H. Monetti ◽

A. Llano-Torre ◽

M.C. Torrijos ◽

G. Giaccio ◽

R. Zerbino ◽

...

Keyword(s):

Reinforced Concrete ◽

Fiber Reinforced Concrete ◽

Fiber Reinforced ◽

Service Conditions ◽

Long Term Behavior

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Long-term bending properties of cross-laminated timber made from Japanese larch under constant environment

Journal of Wood Science ◽

10.1186/s10086-021-01997-1 ◽

2021 ◽

Vol 67 (1) ◽

Author(s):

Ryuya Takanashi ◽

Yoshinori Ohashi ◽

Wataru Ishihara ◽

Kazushige Matsumoto

Keyword(s):

Load Capacity ◽

Creep Rupture ◽

Japanese Larch ◽

Larix Kaempferi ◽

Loading Capacity ◽

Loading Test ◽

Cross Laminated Timber ◽

Duration Of Load ◽

Rupture Behavior

AbstractCross-laminated timber (CLT) has been used extensively in timber construction. CLT panels are typically used in roofs and floors that carry a continuous load, and it is important to examine the long-term loading capacity of CLT. However, studies that focus on the long-term loading capacity of CLT are limited. To this end, we conducted long-term out-of-plane bending tests on seven-layer CLT made from Japanese larch (Larix kaempferi) under constant environmental conditions, investigated creep performance and duration of load, and experimentally analyzed creep rupture behavior. The mean estimated relative creep after 50 years was 1.49. The sample showed a satisfactory resistance to creep as a building material. The duration of load of most of the specimens in this study was shorter than the conventional value of small clear wood specimens. Specimens had a lower duration of load capacity than solid lumber. According to the results of survival analysis, a loading level of 70% or more caused the initial failure of specimens. Creep rupture of most of the specimens occurred at less deflection than displacement at failure in the short-term loading test. Additional studies focusing on the effects of finger joints, transverse layers, and width of a specimen on creep rupture behavior are suggested.

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Durability of Embedded PZTs in Structural Health Monitoring Systems under Cyclic Loading

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.891-892.1255 ◽

2014 ◽

Vol 891-892 ◽

pp. 1255-1260 ◽

Cited By ~ 4

Author(s):

Sanghyun Yoo ◽

Akbar Afaghi Khatibi ◽

Everson Kandare

Keyword(s):

Cyclic Loading ◽

Structural Health Monitoring ◽

Lead Zirconate Titanate ◽

Health Monitoring ◽

Low Cycle Fatigue ◽

Maintenance Cost ◽

Clear Understanding ◽

Structural Health ◽

Service Conditions

Structural Health Monitoring (SHM) systems are developed to decrease the maintenance cost and increase the life of engineering structures by fundamentally changing the way structural inspections are performed. However, this important objective can only be achieved through the consistent and predictable performance of a SHM system under different service conditions. The capability of a Piezoelectric lead Zirconate Titanate (PZT)-based SHM system in detecting structural flaws strongly depends on the sensor signals as well as actuator performance. But service conditions can change the behaviour of transducers, raising questions about long term SHM system capability. Although having a clear understanding of the reliable sensor life is important for surface mounted systems, however, this is particularly critical for embedded sensors. This is due to the fact that opportunity for replacement of sensors exists for surface bonded transducers while for the embedded systems, sensor replacement is not straightforward. Therefore, knowledge of the long term behaviour of embedded-SHM systems is critical for their implementation. This paper reports a study on the degradation of embedded PZT transducers under cyclic loadings. Carbon/epoxy laminates with an embedded PZT were subjected to fatigue loading and their performance was monitored using Scanning Laser Vibrometery (SLV). The functionality of PZT transducers under sensing and actuating modes were studied. High and low cycle fatigue tests were performed to establish strain-voltage relationships which can be used to identify critical cyclic loading parameters (number of cycles and R value) under sensing and actuating modes.

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Experimental testing of a rocking timber shear wall with slip-friction connectors

Earthquake Engineering & Structural Dynamics ◽

10.1002/eqe.2413 ◽

2014 ◽

Vol 43 (11) ◽

pp. 1621-1639 ◽

Cited By ~ 40

Author(s):

Wei Y. Loo ◽

Chern Kun ◽

Pierre Quenneville ◽

Nawawi Chouw

Keyword(s):

Experimental Testing ◽

Shear Wall ◽

Timber Shear Wall

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Influence of Extension of Load Spectrum on Estimation of Residual Fatigue Lifetime of Railway Axle

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.258.607 ◽

2016 ◽

Vol 258 ◽

pp. 607-610

Author(s):

Pavel Pokorný ◽

Pavel Hutař ◽

Luboš Náhlík

Keyword(s):

Load Spectrum ◽

Safe Operation ◽

Fatigue Lifetime ◽

Term Operation ◽

Railway Axle ◽

Tolerance Approach ◽

Curved Track ◽

Service Conditions ◽

Residual Fatigue

Railway axles are subjected to cyclic amplitude loading which can lead to fatigue failure. For safe operation of railway axles a damage tolerance approach taking into account a possible defect in railway axle is often required. Because of different operation regimes of trains (fast/slow ride, ride on straight track, on curved track, over switches etc.) the load amplitude of axle is not constant. The variability of load is defined by a load spectrum, which is determined experimentally by measuring of load in service conditions. Even though the load spectrum is measured on several hundreds or thousands of operation kilometres, the railway axles are in operation much longer time (often tens of years). Therefore, some load amplitudes higher than ones measured in the test can occur during a long-term axle service. The contribution presented deals with the effect of extension of load spectrum by rare high load amplitudes, which can occur during long-term operation, on residual fatigue lifetime of railway axles.

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