Dynamic Response of Bridge-Landslide Parallel System under Earthquake

In order to further understand the instability mechanism and geohazard causation when the main sliding path of the slope body is parallel to the path of the bridge, the corresponding bridge-landslide parallel system is constructed for shaking table tests. This paper summarizes the combination forms of bridge-landslide model under different position and focused on the slope body located above the bridge deck. Firstly, based on the shaking table test results of El Centro (1940), the failure behavior of bridge-landslide parallel system was evaluated, and the changes of acceleration and deformation of bridge pile were subsequently analyzed. Then, the interaction bridge structure and sliding body were explained by the spectral features. The main conclusions are as follows. First, in the model test, the landslide belongs to the thrust-type landslide. Due to the barrier function of the bridge, the main failure site of landslide occurs in the middle and trailing edge of slope body. At the same time, the acceleration value of earthquake waves is 0.3 g, which is the key to this variation. Second, the acceleration response of the measuring points on the bridge pile and landslide increases with the increase of ground elevation. If the slope structure is damaged severely, the deformation response of weak interlayer is inconsistent with the surrounding soil structure. Third, with the increase of excitation power, the dominant frequency of bridge-landslide parallel system gradually transitions from low to high frequency rate, and the interaction of the parallel system weakens the influence of river direction on frequency. Finally, under the same working condition, the dynamic response of the measuring points has obvious regularity with the change of situation. But the response of the same points is not regular due to the different earthquake excitation intensity.

Mechanics of Tubes Composed of Interlocking Building Blocks

Topologically interlocking material (TIM) systems are composed of convex polyhedral units placed such that building blocks restrict each other's movement. Here, TIM tubes are considered as rolled monolayers of such assemblies. The deformation response of these assembled tubes under diametrical loading is considered. This investigation employs experiments on additivelymanufactured physical realizations and finite element analysis with contact interactions. The internal load transfer in topologically interlocking tubes is rationalized through inspection of the distribution of minimum principalstress. A thrust-line (TL) model for the deformation of topologically interlocking tubes is established. The model approximates the deformation response of the assembled tubes as the response of a collection of Misestrusses aligned with paths of maximum load transfer in the system. The predictions obtained with the TL-model are in good agreement with results of finite element models. Accounting for sliding between building blocks in theTL-model yields a predicted response more similar to experimental results with additively manufactured tubes.

Flexoelectric properties of multilayer two-dimensional material MoS2

Two-dimensional (2D) materials exhibit a high strength and flexibility along with unique electrical-mechanical multiphysics properties. In this study, we experimentally demonstrated the electromechanical response of a multilayer 2D material, 2H-phase MoS2, by using a piezoresponse force microscope. In particular, the dominant physical quantity of the deformation response was determined by independently controlling the electric field and electric field gradient by changing the probe shape and material thickness (number of layers). The multilayer MoS2 exhibited an out-of-plane electrical-mechanical deformation response that followed and was inverted with respect to positive and negative voltages, respectively. Moreover, the relationships between the electric field gradient and strain were similar for all shapes of the probe tip and film thickness values. This result indicated that the electrical-mechanical response of this material was dominated by the electric field gradient, and the strain could be attributed to the converse flexoelectric effect. The findings can provide guidance for the realization of ultrathin electromechanical devices.

A Component-Based Model for Novel Modular Connections with Inbuild Component

A modular steel structure building has obvious advantages in reducing construction period and protecting the environment due to its unique construction method, so it is widely used in modern construction. However, the modular building connection design and modeling are mostly based on the traditional connection research results. To address this issue, the paper developed a component-based model for novel modular connections with an inbuild component. First of all, the comprehensive parameter study was implemented using elaborate finite element models. Then the component-based model for novel modular connections was developed, and the force-deformation response of each component was determined using the finite element method. Thirdly, assembly of all components to overall rotational joint and the simplified finite element model of modular connections was obtained. Finally, comparison between simplified and refined finite element was conducted, the results showed that the proposed model can predict the mechanical behavior of modular building connections within the acceptable margin of error.