SS-V:5050 塑性梁的纯弯曲

测试编号:VNL06求出受力矩作用的悬臂梁的弹性核心和最大位移。

定义



Figure 1.

梁尺寸为 b x h x L。

其中,
尺寸
b
=10 mm
h
=40 mm
L
=200 mm
梁的材料为刚性塑性,具有应变-应力曲线 (Figure 2)。


Figure 2.
材料属性为:
属性
屈服应力
σ y MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8qrps0lbbf9q8WrFfeuY=Hhbbf9v8 qqaqFr0xc9pk0xbba9q8WqFfea0=yr0RYxir=Jbba9q8aq0=yq=He9 q8qqQ8frFve9Fve9Ff0dmeaacaGacmGadaWaaiqacaabaiaafaaake aacqaHdpWCdaWgaaWcbaGaamyEaaqabaaaaa@3BA4@ = 2.1188e+8 Pa
屈服应变
ε y MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8qrps0lbbf9q8WrFfeuY=Hhbbf9v8 qqaqFr0xc9pk0xbba9q8WqFfea0=yr0RYxir=Jbba9q8aq0=yq=He9 q8qqQ8frFve9Fve9Ff0dmeaacaGacmGadaWaaiqacaabaiaafaaake aacqaH1oqzdaWgaaWcbaGaamyEaaqabaaaaa@3B88@ = 1.73425e-3
泊松比
0

该研究是针对以下力矩 M MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8qrps0lbbf9q8WrFfeuY=Hhbbf9v8 qqaqFr0xc9pk0xbba9q8WqFfea0=yr0RYxir=Jbba9q8aq0=yq=He9 q8qqQ8frFve9Fve9Ff0dmeaacaGacmGadaWaaiqacaabaiaafaaake aacaWGIbaaaa@399E@ 值进行的:776.893 N*m and 847.518 N*m

参考解

塑性梁弯曲理论假定梁材料中存在两个区域:梁外层的塑性区和梁中心线的弹性核心区。


Figure 3. 未硬化材料的相应应力分布
所施加的力矩 M MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8qrps0lbbf9q8WrFfeuY=Hhbbf9v8 qqaqFr0xc9pk0xbba9q8WqFfea0=yr0RYxir=Jbba9q8aq0=yq=He9 q8qqQ8frFve9Fve9Ff0dmeaacaGacmGadaWaaiqacaabaiaafaaake aacaWGIbaaaa@399E@ 梁中弹性核心尺寸 H MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8qrps0lbbf9q8WrFfeuY=Hhbbf9v8 qqaqFr0xc9pk0xbba9q8WqFfea0=yr0RYxir=Jbba9q8aq0=yq=He9 q8qqQ8frFve9Fve9Ff0dmeaacaGacmGadaWaaiqacaabaiaafaaake aacaWGIbaaaa@399E@ 之间的关系。(1)
M =   σ y * b * ( h 2 / 4     H 2 / 3 ) MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVCI8FfYJH8YrFfeuY=Hhbbf9v8qqaqFr0xc9pk0xbb a9q8WqFfeaY=biLkVcLq=JHqpepeea0=as0Fb9pgeaYRXxe9vr0=vr 0=vqpWqaaeaabiGaciaacaqabeaadaqaaqaaaOqaaabaaaaaaaaape Gaamytaiabg2da9iaacckacqaHdpWCpaWaaSbaaSqaa8qacaWG5baa paqabaGcpeGaaiOkaiaadkgacaGGQaWdamaabmaabaWdbiaadIgapa WaaWbaaSqabeaapeGaaGOmaaaakiaac+cacaaI0aGaaeiiaiabgkHi TiaabccacaWGibWdamaaCaaaleqabaWdbiaaikdaaaGccaGGVaGaaG 4maaWdaiaawIcacaGLPaaaaaa@4929@

其中, b MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8qrps0lbbf9q8WrFfeuY=Hhbbf9v8 qqaqFr0xc9pk0xbba9q8WqFfea0=yr0RYxir=Jbba9q8aq0=yq=He9 q8qqQ8frFve9Fve9Ff0dmeaacaGacmGadaWaaiqacaabaiaafaaake aacaWGIbaaaa@399E@ 是量厚度。

最大挠度:(2)
U m a x =   ε y * L 2 / ( 2 * H ) MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVCI8FfYJH8YrFfeuY=Hhbbf9v8qqaqFr0xc9pk0xbb a9q8WqFfeaY=biLkVcLq=JHqpepeea0=as0Fb9pgeaYRXxe9vr0=vr 0=vqpWqaaeaabiGaciaacaqabeaadaqaaqaaaOqaaabaaaaaaaaape Gaamyva8aadaWgaaWcbaWdbiaad2gacaWGHbGaamiEaaWdaeqaaOWd biabg2da9iaabccacqaH1oqzpaWaaSbaaSqaa8qacaWG5baapaqaba GcpeGaaiOkaiaadYeapaWaaWbaaSqabeaapeGaaGOmaaaakiaac+ca paWaaeWaaeaapeGaaGOmaiaacQcacaWGibaapaGaayjkaiaawMcaaa aa@4623@

结果

塑性梁的弯曲理论是基于平截面在变形过程中保持平面的假设。为了尽可能接近这一基本假设,将问题建模为两个实体的集合。一个实体表示梁本身,其材质属性由曲线定义 (Figure 2)。另一个小实体附着在梁端,并被设置为绝对刚体 (Figure 4)。刚性实体被施加了力矩 M MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8qrps0lbbf9q8WrFfeuY=Hhbbf9v8 qqaqFr0xc9pk0xbba9q8WqFfea0=yr0RYxir=Jbba9q8aq0=yq=He9 q8qqQ8frFve9Fve9Ff0dmeaacaGacmGadaWaaiqacaabaiaafaaake aacaWGIbaaaa@399E@ ,作为力矩传递单元。


Figure 4.
下表总结了下图中描述的模拟结果。
力矩 M [N*m] SOL 参考,弹性核心尺寸 [mm] SimSolid,近似弹性核心尺寸 [mm] % 差异
776.893 10.0 12.0 20.00%
847.518 5.0 6.0 20.00%
力矩 M [N*m] SOL 参考,最大位移 [mm] SimSolid,最大位移 [mm] % 差异
776.893 3.468 3.351 -3.37%
847.518 6.937 6.918 -0.27%
值得一提的是,SimSolid 3D 求解不像在简化梁弯曲公式中那样,在弹性区和塑性区之间没有清晰的边界。这使得直接比较很困难;然而,弹性区的近似大小有很好的相关性。


Figure 5. 应力 X 在 M=776.893 N*m


Figure 6. 应力 X 在 M=847.518 N*m


Figure 7. 米塞斯等效应力在 M=776.893 N*m


Figure 8. 米塞斯等效应力在 M=847.518 N*m


Figure 9. 在 M=776.893 N*m 取消载荷后的残余米塞斯等效应力


Figure 10. 在 M=847.518 N*m 取消载荷后的残余米塞斯等效应力
1 Mase, George E.,“Theory and Problems of Continuum Mechanics(连续体力学的理论和问题)”, McGraw-Hill Company, New York, 1970