Full-field measurement of residual strains in cold bent steel plates
Full-field measurement of residual strains in cold bent steel plates
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DOI：
10.1016/j.jcsr.2016.07.026
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发表时间：
2016-12-01
影响因子：
4.1
通讯作者：
Zoli, T. P.
中科院分区：
文献类型：
--
作者：
Gerbo, E. J.;Thrall, A. P.;Zoli, T. P.
随着最近美国国家公路和运输官员协会桥梁设计规范接受冷弯超临界和非超临界板以及桥梁行业越来越多地使用冷弯，需要更好地了解和预测冷弯钢中的残余应变。然而，测量残余应变是一项具有挑战性的任务，因为弯曲过程通常会干扰传统的仪器。本文介绍了三维数字图像相关（DIC）作为一种新的，非破坏性的方法来测量残余应变在冷弯钢，捕捉全场应变数据具有高精度。DIC用于测量18个冷弯的12.7mm厚的ASTM A36钢板中的残余应变，所述钢板使用压弯机以不同的角度（10度、20度和30度）和板宽度（762 mm和203 mm）弯曲至102 mm的恒定半径。测得的残余应变进行比较，分析预测和二维和三维有限元模型。使用经验证的有限元模型，完成了额外宽度（12.7 mm和140 mm）和厚度（6.35 mm和19.1 mm）的参数研究，以研究这些参数对周向应变、接触压力、应变状态的影响，并提出建模建议。结果用于开发一种基于最终板尺寸预测峰值残余应变的方法-一种有用的质量控制措施。(C)2016爱思唯尔有限公司版权所有
With the recent American Association of State Highway and Transportation Officials bridge design code acceptance of cold bent fracture-critical and nonfracture-critical plates and the increasing use of cold bending by the bridge industry, there is a need to better understand and predict residual strains in cold bent steel. However, measuring residual strains is a challenging task since the bending process typically interferes with conventional instrumentation. This paper introduces three-dimensional Digital Image Correlation (DIC) as a new, non-destructive approach to measuring residual strains in cold bent steel that captures full-field strain data with high accuracy. DIC was used to measure residual strains in 18 cold bent 12.7 mm thick ASTM A36 steel plates, bent using a press-brake to a constant radius of 102 mm with varying angles (10, 20, and 30 degrees) and plate widths (762 mm and 203 mm). The measured residual strains are compared to analytical predictions and both two and three-dimensional finite element models. A parametric study, using the validated finite element models, is completed for additional widths (12.7 mm and 140 mm) and thicknesses (6.35 mm and 19.1 mm) to investigate the effect of these parameters on circumferential strains, contact pressure, strain state, and to make modeling recommendations. Results are used to develop a means of predicting peak residual strains based on the final plate dimensions - a useful quality control measure. (C) 2016 Elsevier Ltd. All rights reserved.