scholarly journals Multiscale modeling of the deformation and failure of composite structures

2018 ◽  
Author(s):  
A. E. Burov ◽  
O. G. Burova
Keyword(s):  
Multiscale Modeling ◽  
Composite Structures ◽  
Deformation And Failure

Experimental Study on Geometries Energy Absorption of Fiber Metal Laminated Mild Steel under Axial Compression

2013 ◽  
Vol 813 ◽  
pp. 165-170
Author(s):  
Muhammad Izani Sahak ◽  
Ahmad Kamely Mohamad ◽  
Abdullah Atiq Ariffin
Keyword(s):  
Experimental Study ◽  
Mild Steel ◽  
Energy Absorption ◽  
Axial Compression ◽  
Composite Structures ◽  
Hybrid Composites ◽  
Compressive Loading ◽  
Deformation And Failure ◽  
Fiber Metal ◽  
The Impact

Crashworthiness is the ability of a structure to protect its occupants during an impact. Depending on the nature of the impact and the vehicle involved, different criteria are used to determine the crashworthiness of the structure. The combination of metal and composite layers is known to displays plastics deformation and failure mode composite layered. The capable of structures to absorb large amount of energy are great interest in an effort to reduce the impact of collision. In this experimental study, an investigation will be carried out on geometries behavior of fiber metal laminated mild steel under axial compression. For structures subjected to compression, energy absorption is highly desirable and will depend on its physical shape. The efficiency is measured in term of the absorption performance that is higher in hybrid composites than in metallic and composite structures. Much of the working assessing the energy absorbing capability of composite materials and structures under compressive loading has been to a greater extent restricted to axis metric tubes. Therefore, it will contribute knowledge on how to design hybrid composite material tubes to develop a stable or controlled compression response under sustained axial loading.

Intragranular three-dimensional stress tensor fields in plastically deformed polycrystals

Science ◽  
2019 ◽  
Vol 366 (6472) ◽  
pp. 1492-1496 ◽  
Author(s):  
Yujiro Hayashi ◽  
Daigo Setoyama ◽  
Yoshiharu Hirose ◽  
Tomoyuki Yoshida ◽  
Hidehiko Kimura
Keyword(s):  
Stress Tensor ◽  
Multiscale Modeling ◽  
Uniform Elongation ◽  
Three Dimensional ◽  
High Energy ◽  
Stress Fields ◽  
Polycrystalline Materials ◽  
Tensor Fields ◽  
Deformation And Failure ◽  
Stress States

The failure of polycrystalline materials used in infrastructure and transportation can be catastrophic. Multiscale modeling, which requires multiscale measurements of internal stress fields, is the key to predicting the deformation and failure of alloys. We determined the three-dimensional intragranular stress tensor fields in plastically deformed bulk steel using a high-energy x-ray microbeam. We observed intragranular local stresses that deviated greatly from the grain-averaged stresses and exceeded the macroscopic tensile strength. Even under deformation smaller than the uniform elongation, the intragranular stress fields were in highly triaxial stress states, which cannot be determined from the grain-averaged stresses. The ability to determine intragranular stress tensor fields can facilitate the understanding and prediction of the deformation and failure of materials through multiscale modeling.

scholarly journals An efficient multiscale modeling framework for nonlinear analyses of composite structures

2018 ◽  
Author(s):  
DC Pham
Keyword(s):  
Multiscale Modeling ◽  
Composite Structures ◽  
Failure Modes ◽  
Global Analysis ◽  
Material Point ◽  
Multiscale Methods ◽  
Local Approach ◽  
Modeling Framework ◽  
Gauss Point ◽  
Load Increment

Traditional multiscale modeling methods of composite structures are based on the global-local approach whereby the global analysis of structures are first performed to determine potential damage regions, followed by local analyses at those regions to identify detailed damage patterns and failure modes. Such an approach does not take into account the localized effects of critical regions on the global analysis and may become less accurate in general. To address better the behavior of local regions on multiscale analyses, homogenization-based multiscale methods are applied. For each load increment, the global problem is solved simultaneously with one Representative Volume Element (RVE) equilibrium problem for each Gauss point of the global mesh. This approach is successful to capture the local behavior at each material point; however, it is computationally expensive since the RVE is called at all the Gauss points in the global model for each load increment. We develop an efficient multiscale modeling method whereby the RVE analyses are only called at specialized locations by multiscale elements and run parallel with the global analysis. The constitutive models of multiscale elements are defined in a user-defined element subroutine (UEL) where stiffnesses of the multiscale elements are unknown at the beginning of the analysis. They can only be obtained by performing a series of RVE analyses for each set of loads received from the global analysis. The advantage of the proposed method is that the stiffnesses of the multiscale elements are directly computed from the RVE analyses and keep updated for each global load increment. The nested multiscale modeling is implemented by Python script and highly capable for nonlinear analysis of composite structures.

Multiscale Modeling of Hybrid Composite Structures

2011 ◽  
Vol 471-472 ◽  
pp. 916-921 ◽  
Author(s):  
Milan Růžička ◽  
Jiří Had ◽  
Viktor Kulíšek ◽  
Ondřej Uher
Keyword(s):  
Multiscale Modeling ◽  
Cross Sections ◽  
Composite Structure ◽  
Hybrid Composite ◽  
Composite Structures ◽  
Unidirectional Composite ◽  
Scale Model ◽  
Practical Applications ◽  
Macro Scale ◽  
3D Composite

A novel type of hybrid composite structure has been developed, experimentally investigated and used for many practical applications. The main supporting elements of composite structures are formed by the stamping process of partially cured and axially-oriented carbon fibre rods. This system can fill relatively thick parts of cross sections of beams without risk of delamination. Typical macroscopic sub-cells are formed in the transversal cross section of the part due to this technology. An advantage of this final 3D composite structure is its high shear strength and stiffness in comparison with thick unidirectional composite parts. To absorb the dynamic energy and increase the damping, a rubber-cork layer can be inserted during production, before the final pressing and curing of the whole part. The final stiffness property of the whole 3D composite is obtained from multiscale modeling. It is based on an averaging process and a homogenization technique in FEA. A parametric study was carried out to determine the influence of the size, orientation and thickness of the cell border winding layer on the components of the global elastic material matrix. A comparison of a numerical analysis prediction with experimental results shows acceptable agreement of the elastic modules. A mezzo scale model can be applied for designing a real part on a macro scale.

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