基于3D打印的连续梁桥V形结构光弹性模型试验研究

Study on photoelastic model test of V-shaped structure of continuous bridge based on 3d printing

针对传统光弹性试验模型制作方法存在的制作周期较长、精确度低以及人工成本较高等问题,提出了一种基于3D打印技术制作精确光弹性试验模型的新方法。通过光弹性模型试验加载及应力冻结法得到了清晰的等差条纹图像,运用光弹性原理测定了模型应力,并与实体有限元计算结果进行了对比分析,得到了V形结构各主要构件的应力分布特点。结果表明通过3D打印技术制作模型取代原有机械加工制作的木制模型,能够有效改善传统光弹性模型制作技术的缺点,在够提高光弹性模型质量的同时能使模型制作成本降低1/2,制作周期缩短2/3;光弹性试验和有限元分析结果较吻合,相互验证了二者的正确性与合理性;V形结构总体受力性能合理,安全储备较大,上下弦杆交汇处由于刚度变化较大,应力集中较明显,建议加强该处配筋。

Aiming at the problems of long production cycle,low accuracy and high labor cost of traditional photoelastic test model making methods,a new method based on 3D printing technology to make accurate photoelastic test model was proposed.Through the photoelastic model test loading and stress freezing method,the clear isochromatic fringe imagewas obtained.The model stresswasmeasured using the principle of photoelasticity and compared with the finite element calculation results,the stress distribution characteristics of the main components of the V-shaped structure were obtained.The results indicated that the use of 3D printing technology to make models to replace the original wooden models made by mechanical processing can effectively improve the shortcomings of traditional photoelastic model making technology,which can improve the quality of photoelastic models and reduce the cost of model making by 1/2,the production cyclewas shortened by 2/3;the results of photoelastic test and finite element analysis were in good agreement,which verify the correctness and rationality of the two methods;the overall mechanical performance of the V-shaped structurewasreasonable,and the safety reserve wasenough.Due to the large change of stiffness at the intersection of the upper and lower chords,the stress concentrationwas obvious,therefore,it is recommended to strengthen the reinforcement at the intersection.