【阿信子程序学习笔记（5）】DLOAD（附代码）

子程序DLOAD施加载荷更为灵活，可采用各种自定义的函数施加载荷。

ABAQUS帮助文档中的介绍如下（我就不翻译了，道友英语都比我好）：

User subroutine DLOAD:

• can be used to define the variation of the distributed load magnitude as a function of position, time, element number, load integration point number, etc.;
• will be called at each load integration point for each element-based or surface-based nonuniform distributed load definition during stress analysis;
• will be called at each stiffness integration point for computing the effective axial force, ESF1, for pipe elements subjected to nonuniform load types PENU and PINU;
• cannot be used in mode-based procedures to describe the time variation of the load; and
• ignores any amplitude references that may appear with the associated step definition or nonuniform distributed load definition.

子程序的接口（User subroutine interface）如下

SUBROUTINE DLOAD(F,KSTEP,KINC,TIME,NOEL,NPT,LAYER,KSPT,

1 COORDS,JLTYP,SNAME)

C

INCLUDE 'ABA_PARAM.INC'

C

DIMENSION TIME(2), COORDS (3)

CHARACTER*80 SNAME

user coding to define F

RETURN

END

如下图所示为采用DLOAD子程序施加了一个心形载荷，阿信希望这次肺炎疫情早日过去，社会重回安定祥和。

心形的函数如下图（来源网络）

载荷施加区域按照正弦和余弦两条路径同时加载（动图很炫，但阿信很懒）

载荷随着时间按照正弦路径加载

话不多说，因为没时间，附上上图的代码，你们可以自己玩其他的花样。