abaqus

Answers to Workshop 1

1/1 Introduction to ABAQUS/Standardand ABAQUS/Explicit

WA1.1

ABAQUS

Answers 1

Basic Input and Output

Question W1–1: What is the processor on your machine?

Answer: It depends on the system you are using.

Question W1–2: What is the operating system (OS) level?

Answer: It depends on the system you are using.

Question W1–3: What are the two example problems that fit this description?

Answer: Problem 1.1.15, Damage and failure of a laminated composite plateProblem 1.2.5, Unstable static problem: reinforced plate undercompressive loads

Question W1–4: In the space provided, write the input to define a node set calledTOP_NODES that contains previously defined nodes 21, 22, 23, and nodeset TOP_LEFT.

Answer: *NSET, NSET=TOP_NODES

21, 22, 23, TOP_LEFT

Question W1–5: In the space provided, write the input to define a velocity boundarycondition on the node set named NALL. The velocity is 7.0 m/s in the2-direction. Will this option appear in the model data or the history dataportion of the input file?

Answer: This option will appear in the history data section of the input file, becauseit is a nonzero boundary condition.

*BOUNDARY, TYPE=VELOCITY

NALL, 2, 2, 7.0



WA1.2

ABAQUS

Question W1–6: (Optional) In the space provided, write the input to define the ∗BEAMSECTION option for beam elements in element set ELBEAMS referring to amaterial named STEEL1. The beam has a rectangular cross-section with aheight of 0.5 m and a width of 0.2 m.

Answer: *BEAM SECTION, SECTION=RECT, ELSET=ELBEAMS,

MATERIAL=STEEL1

0.2, 0.5

Question W1–7: What is the first option in the model data? What is the last option in themodel data?

Answer: The beginning of the model data is the ∗HEADING option. The last optionin the model data is the ∗MATERIAL option in the material option blockthat defines the material properties of the model.

Question W1–8: What is the first option in the history data?

Answer: The history data begins with the ∗STEP option.

Question W1–9: How many steps are there in this analysis?

Answer: There is only one step in this analysis.

Question W1–10: What type of elements are used to model the lug?

Answer: C3D20R elements; i.e., 20-node brick elements (three-dimensionalhexahedral continuum elements) with reduced integration, are used tomodel the lug.

Question W1–11: Do you need to define a density to complete the material definition?Material density is necessary for what types of analysis?

Answer: No. The density is necessary for analysis procedures that consider inertiaeffects. In a static analysis inertia effects are not considered.



WA1.3

ABAQUS

Question W1–12: How else could you define a completely constrained boundary condition?

Answer: “Type” boundary conditions labels (such as ENCASTRE) can be used todefine fixed boundary conditions in the model data. An alternative approachis to specify the fixed degrees of freedom by number. To specify degrees offreedom 1 through 6, you could use the following input in the model data orhistory data:

*BOUNDARY

LHEND, 1, 6

Question W1–13: What version of ABAQUS are you using?

Answer: The version number is available at the top of the printed output (.dat) file.

Question W1–14: What warning messages did you get? Do they require changes to the inputfile, or can you ignore them?

Answer: If you followed the instructions correctly to this point, there are warningmessages in the data (.dat) file indicating that the rotational degrees offreedom—4, 5, and 6—are not active in this model and cannot berestrained. ABAQUS ignores boundary conditions on degrees of freedomthat cannot be restrained; therefore, you can safely ignore these warningmessages.

Question W1–15: How many elements are there in the model? How many variables are there?

Answer: The model has 112 elements. The total number of variables, includingdegrees of freedom plus any Lagrange multiplier variables, is 2376.

Question W1–16: Which elements are in element set HOLEIN?

Answer: Elements 1 and 16.



WA1.4

ABAQUS

Question W1–17: What are the maximum direct stresses in the 1- and 2-directions (i.e., σ11and σ22)?

Answer: The maximum direct stress in the 1-direction (S11) is 3.4766E+08 Pa; themaximum direct stress in the 2-direction (S22) is 8.7629E+07 Pa.

Question W1–18: What is the deflection of node 20001 in node set HOLEBOT inthe 2-direction?

Answer: The deflection is E-04 m.

Question W1–19: What is the net reaction force in the 2-direction at the nodes in node setLHEND? Is this equal to the applied load?

Answer: The reaction forces in the node set LHEND sum to 30 kN, which is equal tothe applied load.

Question W1–20: Why is the sum of the reaction forces at the nodes in node set LHEND in thehorizontal direction (1-direction) zero?

Answer: At the section represented by node set LHEND the reaction forces in thehorizontal direction simply couple to resist the moment induced by theapplied vertical load. Since there is no external load in the horizontaldirection, the reaction forces add up to zero in the horizontal direction.

Question W1–21: What is the deflection of node 20001 in node set HOLEBOT? Do the resultsreflect the reduction in loading?

Answer: The deflection of the nodes in node set HOLEBOT is now reduced to E-04 m. The deflections, reaction forces, and stresses decrease in

proportion to the reduction in loading, in this case by a factor of 2 since thisis a linear analysis.

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