scholarly journals Shear Effects on Energy Dissipation From an Elastic Beam on a Rigid Foundation

2015 ◽  
Vol 83 (1) ◽  
Author(s):  
Adam R. Brink ◽  
D. Dane Quinn

This work describes the energy dissipation arising from microslip for an elastic shell incorporating shear and longitudinal deformation resting on a rough-rigid foundation. This phenomenon is investigated using finite element (FE) analysis and nonlinear geometrically exact shell theory. Both approaches illustrate the effect of shear within the shell and observe a reduction in the energy dissipated from microslip as compared to a similar system neglecting shear deformation. In particular, it is found that the shear deformation allows for load to be transmitted beyond the region of slip so that the entire interface contributes to the load carrying capability of the shell. The energy dissipation resulting from the shell model is shown to agree well with that arising from the FE model, and this representation can be used as a basis for reduced order models that capture the microslip phenomenon.

Author(s):  
Yong Wang ◽  
Huanjun Jiang ◽  
Chen Wu ◽  
Zihui Xu ◽  
Zhiyuan Qin

<p>Suspended ceiling systems (SCSs) experienced severe damage during strong earthquakes that occurred in recent years. The capacity of the ceiling component is a crucial factor affecting the seismic performance of SCS. Therefore, a series of static tests on suspended ceiling components under monotonic and cyclic loadings were carried out to investigate the seismic performance of the ceiling components. The ceiling components include main tee splices, cross tee latches and peripheral attachments. All specimens were tested under axial loading. Additionally, the static tests of cross tee latches subjected to shear and bending loadings were performed due to their seismic vulnerability. The failure pattern, load-carrying ability, deformation capacity and energy dissipation of the ceiling components are presented in detail in this study.</p>


2021 ◽  
Author(s):  
Niklas Bagge ◽  
Jonny Nilimaa ◽  
Silvia Sarmiento ◽  
Arto Puurula ◽  
Jaime Gonzalez-Libreros ◽  
...  

<p>In this paper, experiences on the development of an assessment method for existing bridges are presented. The method is calibrated using the results of full-scale testing to failure of a prestressed bridge in Sweden. To evaluate the key parameters for the structural response, measured by deflections, strains in tendons and stirrups and crack openings, a sensitivity study based on the concept of fractional factorial design is incorporated to the assessment. Results showed that the most significant parameters are related to the tensile properties of the concrete (tensile strength and fracture energy) and the boundary conditions. A finite element (FE) model in which the results of the sensitivity analysis were applied, was able to predict accurately the load-carrying capacity of the bridge and its failure mode. Two additional existing prestressed concrete bridges, that will be used to improve further the method, are also described, and discussed.</p>


Author(s):  
Paul A. Feenstra ◽  
Victor P. Janzen ◽  
Bruce A. W. Smith

Tests are being planned which will use AECL’s MR-3 Freon test facility and a Multi-Span U-Bend (MSUB) test rig to investigate the dynamics of tube vibration in two-phase flow, in particular those mechanisms that can cause excessive damage to steam-generator tubes. In preparation for the tests, free- and forced-vibration tests were conducted to measure the vibration energy dissipation (damping) of a single U-bend tube in air, with dry and wet anti-vibration bars, under a variety of tube-support conditions. This paper presents the relevant damping mechanisms and documents methods used to conduct the tests and to analyze the energy dissipated at the supports. Results indicate that for in-plane motion without tube-to-support contact, viscous damping related to wet AV B supports is much smaller than guidelines based on other types of supports suggest. To begin to examine the effects of the tube coming into contact with its supports, such as friction-related energy dissipation, the results of tests with light tube-to-support preloads are also presented.


2019 ◽  
Vol 16 (1) ◽  
pp. 113-119
Author(s):  
Abdul Rauf ◽  
Syed Ismail Ahmad

The energy dissipated properties of normal and decalcified femur, rib and scapula bones of animals ox and camel have been studied by uniform bending technique. A hysteresis curve has been observed between the elevation in bone and load applied. It is observed that the energy dissipated as calculated from the hysteresis loop for rib is more than that of femur and scapula of ox and camel. It has been observed that the dissipation of energy in normal bone is less than that of decalcified bone under the same condition of applied load. The highest energy dissipation was observed in case of rib bone of camel compared to that of any other bone, rib of camel and scapula of ox dissipates maximum energy than femur bones. The study suggests that this technique is simple, elegant and inexpensive besides accurate in determining viscoelastic properties of bone.


2021 ◽  
Vol 8 ◽  
Author(s):  
Yan-Shuang Yang ◽  
Wei Cheng ◽  
Zhan-Rong Zhang ◽  
Hao-Yuan Tian ◽  
Kai-Yue Li ◽  
...  

The energy dissipation usually occurs during rock failure, which can demonstrate the meso failure process of rock in a relatively accurate way. Based on the results of conventional triaxial compression experiments on the Jinping marble, a numerical biaxial compression model was established by PFC2D to observe the development of the micro-cracks and energy evolution during the test, and then the laws of crack propagation, energy dissipation and damage evolution were analyzed. The numerical simulation results indicate that both the crack number and the total energy dissipated during the loading process increase with confining pressures, which is basically consistent with the experiment results. Two damage variables were presented in terms of the density from other researchers’ results and energy dissipation from numerical simulation, respectively. The energy-based damage variable varies with axial strain in the shape of “S,” and approaches one more closely than that based on density at the final failure period. The research in the rock failure from the perspective of energy may further understand the mechanical behavior of rocks.


2021 ◽  
Vol 20 (2) ◽  
pp. 371-381
Author(s):  
Atabak Pourmohammad Sorkhab ◽  
◽  
Mesut Küçük ◽  
Ali Sari ◽  
◽  
...  

In this study, the out-of-plane response of infill walls that are widely used in Turkey and the surrounding regions were experimentally investigated. Several out-of-plane wall tests were performed in the laboratory, with the walls specimens produced with lateral hollow clay bricks (LHCB) and different mortar qualities. The walls were tested in their out-of-plane (OOP) direction under static load conditions and evaluated based on the load-bearing and energy dissipation capacities, crack propagations, mortar strengths, and initial stiffnesses. These walls are experimentally investigated to understand the effects of the mortar strength on the infill wall structural behaviors and to assess the effectiveness of the out-of-plane strength formulations. It was found that when the mortar strength is low, the first major crack occurs at the mortar, however, because of the arch mechanism efficiency in this situation the OOP load-carrying and energy dissipation capacities of unreinforced walls can be significantly increased. When the first major crack in the wall occurs in the brick itself, the arc mechanism is provided with delicate sections in the brick, which leads to strength decreasing in the walls. In this case, excessive deviations occur in the out-of-plane strength formulations estimates. This study shows that the arc mechanism, the damage start region and progress can change significantly unreinforced masonry (URM) infill walls behaviors.


Author(s):  
Mehmet Emin Arslan ◽  
Elif Ağcakoca ◽  
Merve Şentürk

Reinforced concrete structure systems are usually designed as frame or shear wall-frame systems. It is possible to reduce the deformation and displacement in the system by increasing the structural stiffness. Besides, large displacements on the floors caused by horizontal load are damped by the cracks in these walls. The present paper aims to examine the effects of materials used in the wall construction as well as thickness of the plaster on the behavior of infill walls under cyclic loads. In order to investigate the above mentioned effects, three Infill walls that were produced from three different materials namely, horizontal hollow bricks, pumice blocks and aerated concrete blocks were tested in three setups (without plaster, with 1 cm plaster and 2.5 cm plaster on it). In order to determine pure wall contribution, the infill walls were placed in a steel frame test set-up which was hinged from all four corners and were then exposed to cyclic loads taking into account the displacement controlled loading protocol proposed in FEMA 461. Right after applying the plaster to the infill walls, load carrying and energy dissipation capacities of the walls were examined comparatively. Load-displacement, backbone curve and cumulative dissipated energy curves of each infill walls are generated using the data collected from the experiments and the infill walls behaviors are graphically explained. Test results showed that existence and thickness of plaster significantly affected cyclic behavior of the test walls by increasing energy dissipation capacities and load carrying capacities.


Author(s):  
Min-Han Oh ◽  
Seung-Hwan Boo ◽  
Phill-Seung Lee ◽  
Jong-Min Kim ◽  
Joong-Soo Moon ◽  
...  

A cost effective finite element (FE) procedure is proposed for analysis of load-carrying structures with nonlinear contact and frictional behaviors between large floating offshore structures. The key of the procedure is to use the static condensation technique developed from the Guyan model reduction method. The time for computing contact and friction forces on contact interface areas can be dramatically reduced compared to nonlinear analysis with a full FE model. Two representative applications to offshore projects are presented. One is a problem with nonlinear contact of independent tank support in FLNG hull structures and the second is a sea-fastening system used during offshore dry transportation. The reliability and computing efficiency of the proposed analysis procedure are investigated. It is conclusively confirmed that the proposed procedure is practical for application to actual design of offshore projects.


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