abaqus问答精华（ABAQUS question and answer essence）Q: pre tensioned prestressed reinforced how, please pointing.Q: I see in the document that you want to define a rebar in the InP file, but rebar can only be used for shell, membrane, and, solid, elements. I want to do now is a prestressed cable, not embedded in the shell, membrane, and solid the unit, a zipper but independent. The cable unit is going to use truss, but how do you use rebar on the truss? Please expert pointingAnother problem, I see someone else's InP file, is as follows: *rebar, element=continuum, material=rebar2, name=ubarTop1,1.005e-4,0.15,0.0,0.5,1The second line, the first is setname (Top1), and the second is the cross-sectional area (1.005e-4) of the rebar. What do the third, fourth and fifth mean? (0.15,0,0.5) the last one should be the direction, the 1 direction. Which expert pointed out the first three or four and five respectively?A: exerts prestressing force*initinial, conditions, type=stress, rebarElset, rebar name, the prestress value, the other prestress hold to keep the prestress value unchanged, my understanding is to prevent other members eat the prestress, caused by prestress loss. With this command, this loss is avoided, and the applied prestressing force is applied to the reinforcement.A: thank you, what you say should be put in prestressed rebar above, but I find that the truss unit cannot be defined as rebar, in fact, I think that truss would have when cable engineering prestressed steel strand tension is to play a role, tension, and in ABAQUS, truss itself is taut, without prestressA: I know simulation reinforced when the need to use rebar, but the bar you can do directly with truss to simulate, and LZ said actually just during the construction of prestressed tension is not the real meaning of prestress, such as prestressed bolt etc.. If it is a cable, it may be a mere personal view of the prestressing force.Q: ask: do a space steel frame structure, beam column with beam element, board with shell element, intended to use tie command (common node), but I don't know how to achieve?A: I think you can use *equation to implement the constraints of the shared node, which is defined by this command.A: because I order more, but I want to use CAE, enter the command editor in CAE, and then edit it, write the *equation command, specifying the constrained degrees of freedom (see the standard manual, written very clearly)Where is the difference between "Q:" Response spectrum analysis (response spectrum analysis) and "Modal dynamic analysis" (modal dynamic analysis)? Such as Response, spectrum, analysis, you can design the structure? But what are the Modal dynamic analysis for?A: as far as I know, modal, dynamic, analysis should be modal decomposition method for dynamic analysis. Decomposition of a single degree of freedom system and a finite combination reaction.How does Q:abaqus apply seismic loads?A: can refer to the example of ABAQUS 6.3, Seismic, Analysis, of, a, Concrete, Dam, Gravity, and so onCan use:1. *amplitude, name=amp, and input=seismicdata.dat input seismic waves2. *boundary, type=acceleration, amplitude=amp to apply the load.In <ABAQUS, Example, Problems, Manual>, 2.1.15, Seismic, analysis, of, a,, concrete, gravity, damA: that's a relative problem. You can deduce that kinetic equation,The result is that ANSYS is the relative time history that takes the foundation to fix the relative base of the structure, and the ABAQUS is applied to the boundary, and the absolute time history of the structure is solved. Thus, there is a difference between the applied acceleration and the time history.Applied on the boundary time history acceleration by explicit calculation speed (mainly depends on your CPU ABAQUS STANDERD) which is the explicit calculation, in addition to its EXPLICT module can also see specific examples, analysis of the of a Concrete Gravity Dam Seismic Analysis; ANSYS is used for solving implicit (mainly depends on you the hard disk speed and CPU), and the big storm (the default output should be a lot of data for it), ANSYS/LSDYNA can be used to explicitly calculate.I have worked together for time analysis, with a little experience.Q: my boss asked me to use the concrete damage plasticity model1. In nonlinear analysis, how do I know the damage to the structure and how to obtain the ultimate bearing capacity of the structure?2. How do you determine concrete, compression, damage, and concrete tension damage? None of the two seems to have been tested. If you can ignore compression damage, then the definition of tension damage is important because of the presence of the tension stiffening (the falling segment is relatively long). In ABAQUS's example of gravity dams, the tension, stiffening, and tension damage data seem to have some relationship.3. When defining concrete tension stiffening, I read some of the papers above about the Tesion stiffening specification, saying that if tensiong stiffening is defined too small, convergence will be difficult. However, the size of tensionstiffening is defined in *concrete tension stiffening, and the first two data are remaining, direct, stress, after, cracking, and direct cracking strain.4. Does the tension stiffenig have anything to do with the rate of reinforcement? If yes, what is the relationship like? Thank you all.I think A: damage plasticity model is mainly used in concrete under cyclic loading, the concrete compression damage and concrete tension damage only when tension stiffening seems to need to define, the definition of concrete in uniaxial tension constitutive relation, tension and damage should Never mind. It doesn't seem to have anything to do with the reinforcement ratio.塑性损伤模型既可以模拟循环拟静荷载的情况，也可计算结构在动力荷载（地震、风以及冲击荷载的作用），通过混凝土压缩损伤和混凝土受拉破坏考虑混凝土的拉压异性，张力加劲则可考虑拉伸屈服后的软还阶段本构行为，同样是混凝土损伤全过程的一部分，它与配筋率及网格划分密度的相互关系很大程度上影响到计算的收敛性。
