Bending moment

About: Bending moment is a research topic. Over the lifetime, 14577 publications have been published within this topic receiving 158834 citations. The topic is also known as: bending moment.

Behaviour of diaphragm walls in clay prior to collapse

Abstract: Centrifuge model tests have been used in an attempt to gain a coherent view of the soil-structure interaction behaviour following the excavation of soil in front of a pre-constructed wall. Excavation was simulated by the removal of a suitably heavy fluid from a preformed cavity. The broad replication of stress magnitudes and stress paths permitted the full representation of wall deformation, soil strain and swelling, completing a 50 year full-scale lifespan in under 24 hours of continuous centrifuging. Measurements were made of soil displacement vectors, pore water pressures, wall displacements and bending moments together with forces in props when they were present. These have made possible the validation of simplified ‘geostructural mechanisms’ which offer the same degree of advantage to the designer as does the idealization of heam behaviour encapsulated in engineer's beam theory. A serviceability criterion for soil or wall displacements can be entered into simplified admissible strain fields appropria...

An artificial muscle actuator for biomimetic underwater propulsors.

Abstract: In this paper, we introduce the analytical framework of the modeling dynamic characteristics of a soft artificial muscle actuator for aquatic propulsor applications. The artificial muscle used for this underwater application is an ionic polymer–metal composite (IPMC) which can generate bending motion in aquatic environments. The inputs of the model are the voltages applied to multiple IPMCs, and the output can be either the shape of the actuators or the thrust force generated from the interaction between dynamic actuator motions and surrounding water. In order to determine the relationship between the input voltages and the bending moments, the simplified RC model is used, and the mechanical beam theory is used for the bending motion of IPMC actuators. Also, the hydrodynamic forces exerted on an actuator as it moves relative to the surrounding medium or water are added to the equations of motion to study the effect of actuator bending on the thrust force generation. The proposed method can be used for modeling the general bending type artificial muscle actuator in a single or segmented form operating in the water. The segmented design has more flexibility in controlling the shape of the actuator when compared with the single form, especially in generating undulatory waves. Considering an inherent nature of large deformations in the IPMC actuator, a large deflection beam model has been developed and integrated with the electrical RC model and hydrodynamic forces to develop the state space model of the actuator system. The model was validated against existing experimental data.