Experimental and Finite Element Analysis of External ALC Panel Steel Frames with New Semi-Rigid Connector

In this paper, a new ALC panel connector was proposed. It has a good engineering economy and high fault tolerance. A quasistatic loading experiment was carried out to verify the feasibility of the external ALC panel steel frame under seismic loading. The test phenomena, hysteretic curve, skeleton curve, stiffness degradation, and energy dissipation of two sets of full-scale specimens were analyzed and discussed. Moreover, the simulation of pendulous Z-panel connectors with different thicknesses was carried out using ABAQUS software. The comparison reveals that the semi-rigid connection has a full hysteresis curve, good energy dissipation capacity, and a 15% increase in peak load capacity. Finally, similar results for different thicknesses in the use of pendulous Z-panel connectors reveal that using the 6 mm connector may be the most economical solution for engineering.

Skeletonization via Local Separators

We propose a new algorithm for curve skeleton computation that differs from previous algorithms by being based on the notion of local separators . The main benefits of this approach are that it is able to capture relatively fine details and that it works robustly on a range of shape representations. Specifically, our method works on shape representations that can be construed as spatially embedded graphs. Such representations include meshes, volumetric shapes, and graphs computed from point clouds. We describe a simple pipeline where geometric data are initially converted to a graph, optionally simplified, local separators are computed and selected, and finally a skeleton is constructed. We test our pipeline on polygonal meshes, volumetric shapes, and point clouds. Finally, we compare our results to other methods for skeletonization according to performance and quality.

Seismic Resistance Properties of Improved Dry-Type Beam-Column Joint: An Experimental Research

Dry-type joints are an advanced type of sustainable beam-column connection mode used in the prefabricated concrete frame structural system. This paper proposed an improvement scheme for high-strength bolt dry-type joints and designed a new type of common bolt dry-type joints. A pseudo test involving low-cycle repeated loading is conducted to assess the seismic resistance properties of new joints including damage mode, hysteretic curve, skeleton curve, and ductility factor. Numerical simulation is applied to validate the rationality of experimental results. It is found that when the bending capacity of the end block of the beam is consistent with that of the bolt, the deformation of the bolt will no longer increase greatly after a period of large deformation; at this period, the bolt does not fully enter the plastic stage, but at this time, the end block of the beam begins to appear large cracks and enter the plastic deformation and has good energy dissipation performance.

Seismic Behavior of Extended End-Plate Connections Subjected to Cyclic Loading on the Top-Side of the Column

The extended end-plate connections provide excellent performance in resisting seismic loads in high-risk areas. Most scholars’ experiments and finite element studies on this type of joint are focused on the method of applying displacement loads on the beam tip, while the method of applying displacement on the column side has not been the subject of further study. However, the load transmission mechanism of this type of connection is not completely consistent in actual engineering, as the design concept of “strong column weak beam” does not apply to all joints. Therefore, in this paper, the lateral displacement of the applied column is used to simulate the seismic horizontal force to study the mechanical properties of the connection joints of the “weak column and strong beam” under the limit state of earthquake action. Based on the two internal columns (IC-EP1/2) and two edge columns (EC-EP1/2), the failure modes, strength, stiffness, moment–rotation curve, skeleton curve, ductility, and energy dissipation of this type of connection were studied. Experiment results indicated that this type of connection features semi-rigid and partial strength joints. The connection rotation angle of all specimens in the test exceeds 0.05 rad, which suggests it is an ideal seismic joints. Besides, the relationship between the thickness of the end-plate and the diameter of the bolt has a greater impact on the failure mode of the joint. The finite element (FE) analysis models were established for the above connection. The numerical model was validated against experimental results and showed acceptable consistency.

Seismic Behaviour of Self-Insulating Inner-Framed Bearing Walls with Openings

Study on the seismic performance of five self-insulating inner-framed bearing walls (SIBWs) by low cycle cyclic loading test. The results show that the opening has a significant influence on the hysteretic curve, skeleton curve, stiffness and energy-dissipation capacity of the SIBWs. The failure process of the test wall is characterized by the interaction, transition and weak framework stages, all of which show ductile failure. In theory, based on the equivalent elastic plate model, the calculation method of the wall cracking load is established. Based on the idea of the shear resistance mechanism, the diagonal compression bar model of the rigid frame is proposed, the method of determining the width of the diagonal compression bar is clarified by using the equivalent stiffness method, and the calculation method of the ultimate load of the wall is established. A comparison with the measured values shows that the calculation method is accurate.