| 引用本文: | 刘海华,刘希芝,李维.倾斜薄壁增材过程中基板的热应力数值模拟[J].材料科学与工艺,2023,31(4):70-77.DOI:10.11951/j.issn.1005-0299.20220277. |
| LIU Haihua,LIU Xizhi,LI Wei.Numerical simulation of thermal stress on substrates during tilted thin-wall additive process[J].Materials Science and Technology,2023,31(4):70-77.DOI:10.11951/j.issn.1005-0299.20220277. |
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| 摘要: |
| 利用电弧增材制造技术加工倾斜薄壁时,循环热力效应下,熔覆层与基板结合处应力较为集中,易导致基板变形翘曲,严重影响零部件的成形。为了明确增材倾斜薄壁不同层间偏移量和不同基板厚度下基板的热应力演化,本文采用不锈钢焊丝在Q235基板上进行沉积试验,利用COMSOL建立有限元模型,分析基板横向温度梯度和等效应力的变化。结果表明,基板的横向温度梯度在熔覆层边缘达到最大值,在距离熔覆层中心超过5 mm后趋于最小值；随着层间偏移量的增大,基板的横向温度梯度最大值逐渐减小,但基板上的等效应力逐渐增大；随着基板厚度的增加,基板的横向温度梯度最大值逐渐减小,同一测量点的横向温度梯度和等效应力也随之减小。因此,在倾斜薄壁增材中,不同的层间偏移量主要影响基板上横向温度梯度的分布和熔覆层与基板结合处的等效应力,更大厚度的基板能够有效减小基板上的横向温度梯度,从而减小变形,这对于增材初期倾斜薄壁结构中基板的变形控制具有一定的参考意义。 |
| 关键词: 倾斜薄壁 偏移量 基板厚度 横向温度梯度 等效应力 |
| DOI：10.11951/j.issn.1005-0299.20220277 |
| 分类号:TG444 |
| 文献标识码:A |
| 基金项目:天津市教委科研计划项目(2019KJ011). |
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| Numerical simulation of thermal stress on substrates during tilted thin-wall additive process |
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LIU Haihua1, LIU Xizhi1, LI Wei2
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(1.Tianjin Key Laboratory of Advanced Mechatronics Equipment Technology (Tiangong University), Tianjin 300387, China; 2.Zhejiang University INSIGMA System Engineering Co., Ltd., Hangzhou 310000, China)
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| Abstract: |
| When using arc additive manufacturing technology to process tilted thin walls, the stress at the bond between the cladding layer and the substrate is more concentrated under cyclic thermal effect, which easily leads to substrate deformation and warpage and seriously affects the forming of the parts. This paper uses stainless steel wire for deposition tests on Q235 substrate to clarify the thermal stress evolution of the substrate under different interlayer offsets and different substrate thicknesses of the tilted thin wall, and establishes a finite element model using COMSOL to analyze the changes in the transverse temperature gradient and equivalent force of the substrate. Results showed that the transverse temperature gradient of the substrate reached the maximum value at the edge of the cladding layer and tended to the minimum value after a distance of more than 5 mm from the center of the cladding layer. With the increase in the interlayer offset, the maximum value of the transverse temperature gradient of the substrate gradually decreased, but the equivalent force on the substrate gradually increased. With the increase in the substrate thickness, the maximum value of the transverse temperature gradient on the substrate gradually decreased, and the transverse temperature gradient and the equivalent force at the same measurement point also decreased. Therefore, in the tilted thin-wall additive, the distribution of transverse temperature gradient on the substrate and the equivalent force at the bond between the cladding layer and the substrate are primarily affected by the interlayer offsets, and a thicker substrate can effectively reduce the transverse temperature gradient on the substrate, thus reducing the deformation, which has some reference significance for the deformation control of the substrate in the tilted thin-wall structure at the early stage of additive process. |
| Key words: tilted thin wall offset substrate thickness transverse temperature gradient equivalent force |
