O.Bartier
,
X.Hernot
,
Y.Bekouche
,
G.Mauvoisin
,
R.El Abdi
材料科学技术（英）
Instrumented indentation experiments, where load and depth of penetration are measured continuously, enable an evaluation of mechanical properties such as Young's modulus, hardening exponent and yield stress. This assessment requires a precise knowledge of the true contact area between the indenter and the indented material, which depends on piling-up and sinking-in at the contact boundary. The aim of this work is to propose a new relationship between the penetration depth of a spherical indenter and the contact radius, which is valid for most metals in elastic-plastic and fully plastic regimes. Numerical simulations results of the indentation of an elastic-plastic half-space by a frictionless rigid paraboloìd of revolution show that the contact radius-indentation depth evolution can be represented by a power law. This law depends on the Young's modulus, the hardening exponent and the yield stress of the indented material. In order to use the proposed formulation for experimental spherical indentations, the model is adapted in the case of a rigid spherical indenter.
关键词:
Indentation
,
null
,
null
,
null
Minh-Quy LE
,
Seock-Sam KIM
材料科学技术（英）
Finite element analysis was carried out to investigate the conical indentation response of elastic-plastic solids within the framework of the hydrostatic pressure dependence and the power law strain hardening. A large number of 40 different combinations of elasto-plastic properties with n ranging from 0 to 0.5 and σy/E ranging from 0.0014 to 0.03 were used in the computations. The loading curvature C and the average contact pressure pave were considered within the concept of representative strains and the dimensional analysis. Dimensionless functions associated with these two parameters were formulated for each studied value of the pressure sensitivity. The results for pressure sensitive materials lie between those for Von Mises materials and the elastic model.
关键词:
Finite element analysis
,
null
,
null
,
null
Minh-Quy LE
,
Seock-Sam KIM
材料科学技术（英）
Spherical indentation of ceramic coatings with metallic interlayer was performed by means of axisymmetric finite element analysis (FEA). Two typical ceramic coatings with relatively high and low elastic modulus deposited on aluminum alloy and carbon steel were considered. Various combinations of indenter radius-coating thickness ratios and interlayer thickness-coating thickness ratios were used in the modeling. The effects of the interlayer, the coating and the substrate on the indentation behavior, such as the radial stress distribution along the coating surface as well as the coating interface, and the plastic deformation zone evolution in the substrate were investigated in connection with the above mentioned ratios. The coating cracking dominant modes were also discussed within the context of the peak tensile stresses on the coating surface and on the coating interface.
关键词:
Finite element analysis
,
null
,
null
,
null
王世勋
,
季宝峰
,
王群
宇航材料工艺
doi:10.3969/j.issn.1007-2330.2016.01.009
为了研究纤维柱增强复合材料夹芯结构静态压陷力学行为,通过李兹方法与叠加原理相结合,建立全新的纤维柱增强复合材料夹芯结构的压陷力学模型,该模型回避了计算结构应变能的困难.通过理论计算可以得出,与传统泡沫夹芯结构相比,纤维柱增强复合材料夹芯结构很大程度上限制了压陷区的扩展,降低了结构的压陷损伤,有效提高了结构的剩余强度.
关键词:
局部压陷
,
纤维柱增强泡沫夹芯结构
,
叠加模型
