Y. Wang
,
J. Chen
,
H.B. Li
,
null
金属学报(英文版)
An improved interface cohesive zone model is
developed for the simulation of interface contact, under mixed-mode
loading. A new debonding initiation criterion and propagation of
debonding law, taking into account the pressure stress influence on
contact shear strength, is proposed. The model is implemented in a
finite-element program using subroutine VUINTER of ABAQUS Explicit.
An edge-notch four-point bending process and laminated vibration
damping steel sheet punch forming test are simulated with the
improved model in ABAQUS Explicit. The numerical predictions agree
satisfactorily with the corresponding experimental results.
关键词:
Cohesive zone model
,
null
,
null
,
null
H. Tian
,
J. Wang
,
W.P. Dong
,
J. Chen
,
Z. Zhao
,
G.M. Wu
金属学报(英文版)
Traditionally a rotary forging process is a kind of metal forming method where a conic upper die, whose axis is deviated an angle from the axis of machine, forges a billet continuously and partially to finish the whole deformation. For the rotary forging process simulation, more researches were focused on simulating the simple stage forming process with axisymmetric part geometry. Whereas in this paper, the upper die is not cone-shaped, and the billet is non-axisymmetric. So the movement of the punch is much more complicated than ever. The 3D FEM simulation models for the preforming & final forming processes are set up after carefully studying the complicated movement pattern. Deform-3D is used to simulate the material flow, and the boundary nodal resisting forces calculated by the final stage process simulation is used to analyze the final forming die strength. The CAE analysis of the die shows that the design of the final forming die is not reasonable with lower pre-stress which is easy to crack at the critical corners. An optimum die design is also provided with higher pre-stress, and verified by CAE analysis.
关键词:
numerical simulation
,
null
,
null
J. Wang
,
J. Chen
,
Z. Zhao
,
X.Y. Ruan
金属学报(英文版)
The microstructural evolution of microalloyed steel during hot forging process was investigated using physical simulation experiments. The dynamic recrystallized fraction was described by modifying Avrami's equation, the parameters of which were determined by single hit compression tests. Double hit compression tests were performed to model the equation describing the static recrystallized fraction, and the obtained predicted values were in good agreement with the measured values. Austenitic grain growth was modeled as: Dinc5 = D05 + 1.6 × 1032 t·exp () using isothermal tests. Furthermore, an equation describing the dynamic recrystallized grain size was given as Ddyn = 3771·Z-0.2. The models of microstructural evolution could be applied to the numerical simulation of hot forging.
关键词:
microalloyed forging steel
,
再结晶
,
晶粒长大
