In this paper, a new strengthening technique is proposed: the Steel Plate Energy Absorption Device (SPEAD) system, which is intended to increase the flexural strength of beam and column members in RC frame structures. In this way, while permitting calibration of the strength increase in the beam to comply with the strength hierarchy criteria needed for a proper seismic behaviour it can provide additional energy absorption. A numerical evaluation of the SPEAD system is carried out by means of a refined 3D model built with an advanced nonlinear finite element program. The SPEAD system has been virtually applied (through finite element analyses) to an RC external beam–column joint, representative of typical existing RC buildings, and the numerical results are compared to those of a specimen that was not upgraded and subjected to the same experimental tests. The SPEAD upgraded model provided a strength increment of about 50% with also a strong reduction of bond-slip effects in the joint panel region. This latter, in turn, provided a beneficial increase of ductility. Based on the positive results from numerical simulations, a design method is also provided.

中文翻译：

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钢筋混凝土框架结构抗震加固用钢板吸能装置（SPEAD）的数值评价

在本文中，提出了一种新的加固技术：钢板能量吸收装置 (SPEAD) 系统，旨在增加 RC 框架结构中梁和柱构件的抗弯强度。这样，在允许校准梁中的强度增加以符合适当地震行为所需的强度等级标准的同时，它可以提供额外的能量吸收。SPEAD 系统的数值评估是通过使用先进的非线性有限元程序构建的精细 3D 模型进行的。SPEAD 系统已被虚拟应用（通过有限元分析）到 RC 外部梁柱接头，代表典型的现有 RC 建筑，并将数值结果与未升级并经过相同实验测试的样本进行比较。SPEAD 升级后的模型提供了约 50% 的强度增量，同时还大大降低了接缝面板区域的粘滑效应。后者反过来又有益地增加了延展性。基于数值模拟的积极结果，还提供了一种设计方法。