Products: ABAQUS/Standard ABAQUS/Explicit
C3D4T C3D6T C3D8RHT C3D8RT C3D8T C3D10MT
CAX3T CAX4RHT CAX4RT CAX4T CAX6MHT CAX6MT CAX8T CGAX4RHT CGAX4RT CGAX4T CGAX6MHT CGAX6MT CGAX8T
CPE3T CPE4RHT CPE4RT CPE4T CPE6MHT CPE6MT CPE8HT CPE8T CPEG4RHT CPEG4RT CPEG4T CPEG6MHT CPEG6MT CPEG8T
CPS3T CPS4RT CPS6MT
The planar tests and three-dimensional tests consist of a small block pressed against a larger block that is fixed on the bottom. The smaller block slides horizontally on the larger block according to the prescribed loading and displacement history. The axisymmetric tests are essentially the same except that the sliding structures are rings; the outer ring is shorter axially than the inner ring. Relative motion in the axisymmetric tests is in the axial direction for the tests of axisymmetric elements or has axial and circumferential components for the tests of axisymmetric elements with twist. A smoothing factor of 0.05 is used on the contact pairs. For the three-dimensional tests a three-dimensional model with width 1.0 is used. The width of the bottom block is chosen slightly larger to ensure that the upper block contacts the lower block.
The mesh in Figure 1.6.7–1, used for planar tests, is representative of all meshes used in these tests.
Material:Solid
Linear elastic, Young's modulus = 30.0 × 106, Poisson's ratio = 0.3, conductivity = 10.0, density = 1000.0, specific heat = 0.001.
Interface
Friction coefficient (nonzero only for the frictional heat generation tests), 
=0.1.
Gap conductance varies with pressure for the interface conductance tests, k(p=200) = 5.0, k(p=100) = 20.0.
Gap conductance (for the frictional heat generation tests), 20.0.
Gap radiation constants (for the interface radiation tests only), 
=
=1.0 × 10–6, with absolute zero at 
=–273.16.
Step 1, TRANSIENT:
A downward pressure of 100 is applied on top of the smaller block, and a flux of 100 is applied into the smaller block through its surface. The center element of the large block has a film condition with a film coefficient of 10.0 and sink temperature of 0.0 at the bottom face. This step is used to check the gap conductivity. Results should be symmetric about an axis that is parallel to the line joining the centers of the two blocks, and thermal equilibrium must be satisfied.
The heat conducted away from the larger block via the film condition should nearly equal the heat conducted through the interface—they need not be exactly equal because transient effects are included in this step. Input file eia2tssc.inp illustrates the use of the FILM AMPLITUDE parameter with the *FILM option to specify a time-dependent variation of the film coefficient.
Step 2, TRANSIENT:
The top block is made to slide horizontally, back and forth, over the bottom block to assure that the formulation does not fail under large relative sliding. The results are consistent with thermal equilibrium. In the tests of axisymmetric elements with twist, the top block slides with circumferential motion as well.
Step 3, STEADY STATE:
The top block is in the same configuration as at the end of Step 1 but is brought to steady state to eliminate transient effects. This allows for a more exact check on thermal equilibrium of the assembly because the heat conducted across the interface must equilibrate the heat passed into the assembly by the applied flux.
Step 4, STEADY STATE:
The pressure is increased on the top surface. This is designed to test pressure-dependent interface conductivity. The temperature change across the interface should be four times that at the end of Step 3 because the interface conductivity is reduced by one-fourth.
Step 5, TRANSIENT:
The applied flux is ramped down quickly, and the small block is made to slide off the larger block. This is to test that the interface heat transfer is eliminated when a slave node slides off the end of the corresponding master surface. The smaller block becomes insulated, and the temperature is constant throughout the block.
The loading is the same for these tests as for the interface conductance tests. These problems are designed to test radiation heat transfer in the interface. Since the radiative properties are not pressure dependent, the results for Step 4 are identical to Step 3 in these runs.
In this analysis the top (outer) surface of the smaller block is constrained to remain straight and nonrotating via constraint equations specified with the *EQUATION option. In this analysis the LAGRANGE friction formulation is used. With this formulation all relative motion is converted into heat. The default friction algorithm uses an automatic penalty method, allowing small relative motions without dissipation. In these tests this would cause the generated heat to be underestimated by about 0.7%.
Step 1:
A downward force of 200 is applied to the top surface to establish contact (an inward force of 275 is applied for the axisymmetric tests). Virtually no heat generation occurs.
Step 2:
The top block is made to slide back and forth with friction. Assuming Coulomb friction, a total of 120 units of heat is generated. Of this generated heat 60 units are absorbed by the contacting bodies because the fraction of frictional dissipation converted to heat is specified to be 0.5. Results are consistent with thermal equilibrium. In the tests of axisymmetric elements with twist, the top block slides with both axial and circumferential components of motion. The magnitude of the relative motion and the resulting heat generation is the same as in the remaining tests.
STEP 3:
The assembly sits without thermal loading to reach steady state. Because the assembly is adiabatic, it should attain a constant temperature. Based on the amount of heat generated and the heat capacity of the material, the final temperature of the assembly should be 7.5 for the planar case and 0.68 for the axisymmetric case.
A transient simulation is performed for each step. The simulation time for those steps where ABAQUS/Standard performs a steady-state analysis is chosen so that enough time is allowed for the ABAQUS/Explicit solution to reach steady-state conditions. Mass scaling is used to obtain an efficient solution. The rate at which the top block is forced to slide over the bottom block is reduced to ensure a quasi-static response; the amount of relative sliding between the two blocks (and, therefore, the amount of frictional heat generation, for example) is unaffected by this change. Both kinematic and penalty mechanical contact are considered.
C3D8RHT elements.
C3D8RHT elements using surface-to-surface contact.
C3D8RT elements.
C3D8RT elements using surface-to-surface contact.
C3D8T elements.
C3D8T elements using surface-to-surface contact.
CAX4RHT elements.
CAX4RT elements.
CAX4T elements.
CAX4T elements using surface-to-surface contact.
CAX6MHT elements.
CAX6MT elements.
CAX6MT elements using surface-to-surface contact.
CAX8T elements.
CAX8T elements using surface-to-surface contact.
CAX8T, SAX2T elements.
CGAX4RHT elements.
CGAX4RHT elements using surface-to-surface contact.
CGAX4RT elements.
CGAX4T elements.
CGAX4T elements using surface-to-surface contact.
CGAX6MHT elements.
CGAX6MT elements.
CGAX6MT elements using surface-to-surface contact.
CGAX8T elements.
CGAX8T elements using surface-to-surface contact.
CPE4RHT elements.
CPE4RT elements.
CPE4T elements.
CPE4T elements using surface-to-surface contact.
CPE6MHT elements.
CPE6MT elements.
CPE8HT elements.
CPE8T elements.
CPE8T elements using surface-to-surface contact.
CPE8T elements.
CPEG4RHT elements.
*POST OUTPUT analysis.
CPEG4RT elements.
CPEG4T elements.
CPEG6MHT elements.
CPEG6MT elements.
CPEG6MT elements using surface-to-surface contact.
CPEG8T elements.
CPEG8T elements using surface-to-surface contact.
CPS4RT elements.
CPS6MT elements.
C3D8RHT elements.
C3D8RHT elements using surface-to-surface contact.
C3D8RT elements using surface-to-surface contact.
C3D8RT elements.
C3D8T elements.
C3D8T elements using surface-to-surface contact.
CAX4RHT elements.
CAX4RT elements.
CAX4T elements.
CAX4T elements using surface-to-surface contact.
CAX6MHT elements.
CAX6MT elements.
CAX6MT elements using surface-to-surface contact.
CAX8T elements.
CAX8T elements using surface-to-surface contact.
CAX8T, SAX2T elements.
CGAX4RHT elements.
CGAX4RT elements.
CGAX4T elements.
CGAX6MHT elements.
CGAX6MT elements.
CGAX8T elements.
CPE4RHT elements.
CPE4RT elements.
CPE4T elements.
CPE4T elements using surface-to-surface contact.
CPE6MHT elements.
CPE6MT elements.
CPE8T elements.
CPE8T elements using surface-to-surface contact.
CPE8T elements.
CPEG4RHT elements.
CPEG4RT elements.
CPEG4T elements.
CPEG6MHT elements.
CPEG6MT elements.
CPEG8T elements.
CPEG8T elements using surface-to-surface contact.
CPS4RT elements.
CPS6MT elements.
CPS6MT elements using surface-to-surface contact.
S8RT elements.
S8RT elements using surface-to-surface contact.
C3D8RHT elements.
C3D8RHT elements using surface-to-surface contact.
C3D8RT elements.
C3D8T elements.
C3D8T elements using surface-to-surface contact.
CAX4RHT elements.
CAX4RT elements.
CAX4T elements.
CAX6MHT elements.
CAX6MT elements.
CAX8T elements.
CAX8T, SAX2T elements.
CGAX4T elements.
CGAX4T elements using surface-to-surface contact.
CGAX6MT elements.
CGAX8T elements.
CPE4RHT elements.
CPE4RT elements.
CPE4T elements.
CPE4T elements using surface-to-surface contact.
CPE6MHT elements.
CPE6MT elements.
CPE8T elements.
CPE8T elements.
CPEG4T elements.
CPEG8T elements.
CPS4RT elements.
CPS6MT elements.
CAX3T elements.
CAX4RT elements.
CAX6MT elements.
CPE3T elements.
CPE4RT elements.
CPE6MT elements.
CPS3T elements.
CPS4RT elements.
CPS6MT elements.
C3D4T elements.
C3D6T elements.
C3D8RT elements.
C3D10MT elements.
CAX3T elements.
CPE4RT elements.
CPE6MT elements.
C3D4T elements.
CAX3T elements.
CAX4RT elements.
CAX6MT elements.
CPE3T elements.
CPE4RT elements.
CPE6MT elements.
CPS3T elements.
CPS4RT elements.
CPS6MT elements.
C3D4T elements.
C3D6T elements.
C3D8RT elements.
C3D10MT elements.
CAX4RT elements.
CPS4RT elements.
CPS6MT elements.
C3D6T elements.
CAX3T elements.
CAX4RT elements.
CAX6MT elements.
CPE3T elements.
CPE4RT elements.
CPE6MT elements.
CPS3T elements.
CPS4RT elements.
CPS6MT elements.
C3D4T elements.
C3D6T elements.
C3D8RT elements.
C3D10MT elements.
CAX4RT elements.
CAX6MT elements.
CPE3T elements.
C3D8RT elements.
