Effect of Strain Accumulation on Deformation Capacity of RC Flexural Members

应变累积对钢筋混凝土受弯构件变形能力的影响

• 批准号: 09650639
• 负责人: NOMURA Setsuro
• 金额: $ 0.83万
• 依托单位: Science Univ.of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650639/
• 关键词: Deformation Capacity; Reinforced Concrete; Strength Deterioration; Cyclic Loading; Strain Accumulation; Flexural Yielding; Failure Mode; 曲げ降状; 変形能力

Failure mechanism of RC members subjected to reversed cyclic loading after flexural yielding was discussed. Under reversed cyclic loading, a resistance mechanism similar to that under monotonic loading repeats temporary disappearance and rebuilding in the plastic hinge region before strength deterioration. Strength deterioration occurred when the resistance mechanism could not be rebuilt after the temporary disappearance. It was considered that accumulated strain in the plastic region inhibited the rebuilding. The strain accumulation occurred in the low load region just after the reversed loading where the rebuilding took place. The accumulated strain was considered to be an error of the rebuilding of the resistance mechanism. When the error of rebuilding was accumulated enough, it became impossible to rebuild the resistance mechanism.The failure mechanism is different from the failure mode that is caused by destruction of the resistance mechanism provided by increasing bending moment or shear force. On the other hand, the observed failure mode is not caused by destruction of the resistance mechanism but caused by impossibility of the rebuilding provided by accumulated errors of the rebuilding.

讨论了钢筋混凝土构件在反向循环荷载作用下弯曲屈服后的破坏机理。在反向循环载荷下，类似于单调载荷下的阻力机制在强度劣化之前在塑性铰链区域重复暂时消失和重建。当抵抗机制暂时消失后无法重建时，强度就会下降。人们认为塑性区域的累积应变抑制了重建。应变累积发生在发生重建的反向加载之后的低载荷区域。累积的应变被认为是阻力机制重建的错误。当重建误差积累到足够多时，就不可能重建阻力机构。这种失效机制不同于通过增加弯矩或剪力而破坏阻力机构而导致的失效模式。另一方面，观察到的故障模式不是由阻力机制的破坏引起的，而是由重建的累积误差所提供的重建的不可能引起的。

项目成果

田中敬人・衣笠秀行・野村誠郎: "繰り返し載荷下におけるRC梁部材横補強筋の拘束効果劣化性状" コンクリート工学年次論文報告集. (1999)

Takahito Tanaka、Hideyuki Kinugasa 和 Seiro Nomura：“重复荷载作用下 RC 梁构件水平钢筋约束效应的恶化特征”混凝土工程年度报告（1999 年）。

Norito Tanaka Hideyuki Kinugasa Setsuro Nomura: "Deterioration in confinement effectiveness of RC beam under reversed cyclic loading" Proceedings of Japan Concrete Institute. (1999)

Norito Tanaka Hideyuki Kinugasa Setsuro Nomura：“反向循环荷载下 RC 梁的约束有效性恶化”日本混凝土学会论文集。

田中敬人・衣笠秀行・野村設郎: "繰り返し載荷下におけるRC梁部材横補強節の拘束効果劣化性状" コンクリート工学年次論文報告集. (1999)

Takahito Tanaka、Hideyuki Kinugasa 和 Setsuro Nomura：“反复荷载作用下 RC 梁构件侧向钢筋节点约束效应的恶化特征”混凝土工程年论文集（1999 年）。