Effect of Adhesive Thickness on Interfacial Fracture of Bonded Steel Joints

2010 ◽  
Author(s):  
Gefu Ji ◽  
Zhenyu Ouyang ◽  
Guoqiang Li ◽  
Su-Seng Pang ◽  
Samuel Ibekwe
Keyword(s):  
Fracture Mechanics ◽  
Fracture Energy ◽  
Interfacial Fracture ◽  
Critical Parameters ◽  
Bonded Joints ◽  
Cohesive Law ◽  
Nonlinear Fracture Mechanics ◽  
Nonlinear Fracture ◽  
Cohesive Laws ◽  
Adhesive Thickness

The interfacial fracture of bonded structures is a critical issue for the extensive applications to a variety of modern industries. In the recent two decades, nonlinear fracture mechanics methods have been receiving intensive attentions for adhesively bonded joints. Extensive experimental efforts have been made to determine the toughness of adhesive joints. Several experimental studies have also been conducted to determine the interface cohesive law in bonded joints. However, very few studies investigated the effect of adhesive thickness on the interface cohesive laws. In the cohesive law, both fracture energy and the interfacial cohesive strength, as two critical parameters, have significant effect on the fracture behavior and joint’s structural capability. The present study presents the experimental investigation into how the adhesive’s thickness affect these two important parameters with the nonlinear fracture mechanics. At the mean time, the equivalent interface cohesive laws are experimentally determined for the bonded joints with various adhesive thicknesses. The experimental cohesive laws may provide valuable baseline data for simple analytical and numerical cohesive zone models. With the test results, the mechanism for the intrinsic fracture energy and plastic energy dissipation is discussed. Several other interesting conclusions are also obtained.

Effect of Bondline Thickness on Interfacial Fracture of Laminated Composite Materials

2010 ◽  
Author(s):  
Gefu Ji ◽  
Zhenyu Ouyang ◽  
Guoqiang Li ◽  
H. Dwayne Jerro ◽  
Su-Seng Pang
Keyword(s):  
Fracture Mechanics ◽  
Fracture Energy ◽  
Experimental Studies ◽  
Interfacial Fracture ◽  
Critical Parameters ◽  
Bonded Joints ◽  
Cohesive Law ◽  
Nonlinear Fracture Mechanics ◽  
Nonlinear Fracture ◽  
Cohesive Laws

The interfacial fracture of bonded structures is a critical issue for the extensive applications to a variety of modern industries. In the recent two decades, nonlinear fracture mechanics methods have been receiving intensive attentions for adhesively bonded joints. Extensive experimental efforts have been made to determine the toughness of adhesive joints. Several experimental studies have also been conducted to determine the interface cohesive law in bonded joints. However, very few studies investigated the effect of adhesive thickness on the interface cohesive laws. In the cohesive law, both fracture energy and the interfacial cohesive strength, as two critical parameters, have significant effect on the fracture behavior and joint’s structural capability. The present study presents the experimental investigation into how the adhesive’s thickness affect these two important parameters with the nonlinear fracture mechanics. The equivalent interface cohesive laws are experimentally determined for the bonded joints with various adhesive thicknesses. The experimental cohesive laws may provide valuable baseline data for simple analytical and numerical cohesive zone models. Based on the test results, the mechanism for the intrinsic fracture energy and plastic energy dissipation is discussed. Several other interesting conclusions are also obtained.

scholarly journals Aplikasi Size Effect Law Pada Beton Marine dengan Pola Bukaan Tarik

2021 ◽  
Vol 28 (2) ◽  
pp. 143-154
Author(s):  
Fella Supazaein ◽  
Resmi Bestari Muin
Keyword(s):  
Fracture Mechanics ◽  
Size Effect ◽  
Fracture Energy ◽  
High Performance ◽  
High Performance Concrete ◽  
Actual Performance ◽  
Nonlinear Fracture Mechanics ◽  
Nonlinear Fracture ◽  
Sample Height ◽  
Marine Concrete

AbstrakPengembangan infrastruktur di bidang maritim adalah salah satu strategi untuk mengembangkan perekonomian. Beton marine banyak digunakan sebagai material struktur  pada pembangunan infrastruktur di bidang maritim tersebut. Beton marine harus menggunakan beton high performance concrete (HPC). Dengan berkembangnya teknologi beton HPC pengoptimalan efisiensi komponen struktur menjadi lebih signifikan.Pada perencanaan pelaksanaan pembangunan khususnya pada tahap analisa struktur, jarang sekali direncanakan kekuatan terhadap mekanika fraktur yang seharusnya juga didesain agar keruntuhan secara fraktur bisa diatasi. penelitian ini mengkaji aplikasi size effect law pada beton HPC pada balok  dengan berbagai ukuran yang sudah ditentukan (small, medium dan high) untuk memperoleh nilai energy fraktur (Gf). Hasil penelitian ini dapat berkontribusi dalam penerapam metode untuk mendapatkan nilai parameter dari kinerja fraktur. selain itu, data parameter dapat digunakan dalam mengkalibrasi analisa numerik elemen struktur berbasis fraktur energi agar dapat dipastikan kinerja struktur yang sesungguhnya.Hasil pengujian menunjukkan energi fraktur pada benda uji set II (rasio takik terhadap tinggi sample = 1/6) lebih besar 8,4% dari benda uji set I (rasio takik terhadap tinggi sample = 1/3). Factor geometri  dan kemiringan pada garis regresi (A) menurun selaras dengan menurunnya rasio takik. Dari angka keruntuhan nilai  berada pada range 0,1 <  < 10 yang menandakan material didesain harus dengan kriteria nonlinear fracture mechanic.Kata-kata Kunci: Beton marine, mekanika fraktur, size effect law, nonlinear fracture mechanics AbstractInfrastructure development in the maritime sector is one strategy for developing the economy. Marine concrete is widely used as a structural material in infrastructure development in the maritime sector. Marine concrete must use high performance concrete (HPC). With the development of HPC concrete technology, optimization of the efficiency of structural components has become more significant.In the construction implementation planning, especially at the structural analysis stage, it is rare to plan the strength of the fracture mechanics which should also be designed so that fracture collapse can be overcome. This study examines the application of size effect law on HPC concrete on beam of various predetermined sizes (small, medium and high) to obtain the fracture energy value (Gf). The results of this study can contribute to the application of the method to obtain parameter values of fracture performance. In addition, parameter data can be used in calibrating the numerical analysis of energy fracture based structural elements in order to ascertain the actual performance of the structure.The results showed that fracture energy in specimen set II (ratio of notches to depth = 1/6) was 8.4% greater than specimen set I (ratio of notches to sample height = 1/3). The geometric factor  and slope of the regression line (A) decreased in line with the decreasing notch ratio. From the brittleness number, the value of β is in the range 0.1 <β <10 which indicates that the material should  designed with nonlinear fracture mechanic criteria.Key words: marine concrete, fracture mechanics, size effect law, nonlinear fracture mechanics

Effects of Adhesive Thickness on Global and Local Mixed Mode I/II Interfacial Fracture of Bonded Steel Joints

2011 ◽  
Author(s):  
Gefu Ji ◽  
Zhenyu Ouyang ◽  
Guoqiang Li ◽  
Wei Xu ◽  
Dwayne Jerro ◽  
...  
Keyword(s):  
Numerical Models ◽  
Interfacial Strength ◽  
Interfacial Fracture ◽  
Critical Parameters ◽  
Interface Fracture ◽  
Bonded Joints ◽  
Fracture Behaviors ◽  
Adhesive Thickness ◽  
Global And Local ◽  
Interfacial Traction

Interfacial toughness and interfacial strength, as two critical parameters in an interfacial traction-separation law, have important effect on the fracture behaviors of bonded joints. In this work, the global and local tests are employed to investigate the effect of adhesive thickness on interfacial energy release rate, interfacial strength, and shapes of the interfacial traction-separation laws. Basically, the measured laws in this work reflect the equivalent and lumped interfacial fracture behaviors which include the cohesive fracture, damage and plasticity. The experimentally determined interfacial traction-separation laws may provide valuable baseline data for the parameter calibrations in numerical models. The current experimental results may also facilitate the understanding of adhesive thickness-dependent interface fracture of bonded joints.

Complex study of the fracture processes in materials and structures

2018 ◽  
Vol 84 (11) ◽  
pp. 46-51 ◽  
Author(s):  
N. A. Makhutov
Keyword(s):  
Fracture Mechanics ◽  
Crack Resistance ◽  
Scientific Basis ◽  
Intensity Factors ◽  
Nonlinear Fracture Mechanics ◽  
Nonlinear Fracture ◽  
Linear Fracture ◽  
Science Technology ◽  
Fracture Processes

The results of comprehensive studies of multifactor processes, mechanisms and criteria for fracture at a variation of the crack-like defect state, loading conditions and mechanical properties of structural materials carried out in the 20th - 21st centuries are presented on the basis of monographic publications and articles published in the journal “Zavodskaya Laboratoriya. Diagnostika Materialov.” Crack resistance of materials and structures has become a key problem of the material science, technology, design, manufacture and service of structures. Fracture mechanics including estimation of the stress-strain and limiting states in a cracks tip formed a scientific basis of the crack resistance analysis Stress intensity factors (linear fracture mechanics) and strain intensity factors (nonlinear fracture mechanics) are accepted as the basic criteria of those states. The basic computational relations for construction of the fracture diagrammes which link the cracks growth with conditions of a static, cyclic, long-term, dynamic loading are presented. Parameters of computational relations are put into correspondence with the features of fracture processes on nano-, micro-, meso- and macrolevels. Prospects of the research and guidelines of further studing crack resistance are discussed.

Nonlinear Fracture Mechanics Analysis Considering Material Inhomogeneity of Welded Joints

Impact ◽  
2019 ◽  
Vol 2019 (10) ◽  
pp. 105-107
Author(s):  
Hiroshi Okada
Keyword(s):  
Fracture Mechanics ◽  
Solid Mechanics ◽  
Crack Nucleation ◽  
Intensity Factors ◽  
Nonlinear Fracture Mechanics ◽  
Material Inhomogeneity ◽  
Computational Fracture Mechanics ◽  
New Methods ◽  
Nonlinear Fracture ◽  
Mechanics Analysis

Professor Hiroshi Okada and his team from the Department of Mechanical Engineering, Faculty of Science and Technology, Tokyo University of Science, Japan, are engaged in the field of computational fracture mechanics. This is an area of computational engineering that refers to the creation of numerical methods to approximate the crack evolutions predicted by new classes of fracture mechanics models. For many years, it has been used to determine stress intensity factors and, more recently, has expanded into the simulation of crack nucleation and propagation. In their work, the researchers are proposing new methods for fracture mechanics analysis and solid mechanics analysis.

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