Numerical modeless of the damage, around inclusion in the orthopedic cement PMMA

Cherfi Mohamed,Benbarek Smail,Bachir Bouiadjra,B. Serier 국제구조공학회 2016 Structural Engineering and Mechanics, An Int'l Jou Vol.57 No.4

In orthopedic surgery and more especially in total arthroplastie of hip, the fixing of the implants generally takes place essentially by means of constituted surgical polymer cement. The damage of this materiel led to the fatal rupture and thus loosening of the prosthesis in total hip, the effect of over loading as the case of tripping of the patient during walking is one of the parameters that led to the damage of this binder. From this phenomenon we supposed that a remain of bone is included in the cement implantation. The object of this work is to study the effect of this bony inclusion in the zones where the outside conditions (loads and geometric shapes) can provoke the fracture of the cement and therefore the aseptic lousing of the prosthesis. In this study it was assumed the presence of two bones –type inclusions in this material, one after we analyzed the effect of interaction between these two inclusions damage of damage to this material. One have modeled the damage in the cement around this bone inclusion and estimate the crack length from the damaged cement zone in the acetabulum using the finite element method, for every position of the implant under the extreme effort undergone by the prosthesis. We noted that the most intense stress position is around the sharp corner of the bone fragment and the higher level of damage leads directly the fracture of the total prosthesis of the hip.

Numerical simulation of the femur fracture under static loading

Zagane Mohammed El Sallah,Benbarek Smail,Sahli Abderahmane,B. Bachir Bouiadjra,Serier Boualem 국제구조공학회 2016 Structural Engineering and Mechanics, An Int'l Jou Vol.60 No.3

Bone is a living material with a complex hierarchical structure that gives it remarkable mechanical properties. Bone constantly undergoes mechanical. Its quality and resistance to fracture is constantly changing over time through the process of bone remodeling. Numerical modeling allows the study of the bone mechanical behavior and the prediction of different trauma caused by accidents without expose humans to real tests. The aim of this work is the modeling of the femur fracture under static solicitation to create a numerical model to simulate this element fracture. This modeling will contribute to improve the design of the indoor environment to be better safe for the passengers’ transportation means. Results show that vertical loading leads to the femur neck fracture and horizontal loading leads to the fracture of the femur diaphysis. The isotropic consideration of the bone leads to bone fracture by crack propagation but the orthotropic consideration leads to the fragmentation of the bone.

Fracture behavior modeling of a 3D crack emanated from bony inclusion in the cement PMMA of total hip replacement

Mohamed, Cherfi,Abderahmane, Sahli,Benbarek, Smail Techno-Press 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.66 No.1

In orthopedic surgery and in particular in total hip arthroplasty, the implant fixation is carried out using a surgical cement called polymethylmethacrylat (PMMA). This cement has to insure a good adhesion between implant and bone and a good load distribution to the bone. By its fragile nature, the cement can easily break when it is subjected to a high stress gradient by presenting a craze zone in the vicinity of inclusion. The focus of this study is to analyze the effect of inclusion in some zone of cement in which the loading condition can lead to the crack opening leading to their propagation and consequently the aseptic loosening of the THR. In this study, the fracture behavior of the bone cement including a strange body (bone remain) from which the onset of a crack is supposed. The effect of loading condition, the geometry, the presence of both crack and inclusion on the stress distribution and the fracture behavior of the cement. Results show that the highest stresses are located around the sharp tip of bony inclusion. Most critical cracks are located in the middle of the cement mantle when they are subjected to one leg standing state loading during walking.

Influence of porosity on the behavior of cement orthopaedic of total hip prosthesis

Ali, Benouis,Boualem, Serier,Smail, Benbarek Techno-Press 2015 Biomaterials and biomedical engineering Vol.2 No.4

This paper presents three-dimensional finite element method analyses of the distribution of equivalents stress of Von Mises. Induced around a cavity located in the bone cement polymethylmethacrylate (PMMA). The presences and effect of its position in the cement was demonstrated, thus on the stress level and distribution. The porosity interaction depending on their positions, and their orientations on the interdistances their mechanical behaviour of bone cement effects were analysed. The obtained results show that micro-porosity located in the proximal and distal zone of the prosthesis is subject to higher stress field. We show that the breaking strain of the cement is largely taken when the cement, containing the porosities very close adjacent to each other.

Additive Action of Royal Jelly and Honey Against Staphylococcus aureus

Laid Boukraa,Abdellatif Niar,Hama Benbarek,Mokhtar Benhanifia 한국식품영양과학회 2008 Journal of medicinal food Vol.11 No.1

Four varieties of honey and one variety of freshly reaped royal jelly (RJ) were used to evaluate their additiveaction against Staphylococcus aureus(ATCC 29523). In a first step honey and RJ were used separately to determine theirminimum inhibitory concentration (MIC) against the tested strain. In a second step, lower concentrations of honey than theMIC were added to lower concentrations of RJ than the MIC and then incorporated into media to determine the minimum ad-ditive inhibitory concentration. When tested separately, the MIC of the four varieties of honey ranged between 20% and 21%(vol/vol), and that of RJ was 2% (vol/vol). When used jointly, all honey varieties had a more than 50% decrease in MIC with1% (vol/vol) RJ. A strong linear correlation was noted between the MIC decrease of all varieties of honey and RJ.

Initiation and propagation of a crack in the orthopedic cement of a THR using XFEM

Gasmi, Bachir,Abderrahmene, Sahli,Smail, Benbarek,Benaoumeur, Aour Techno-Press 2019 Advances in computational design Vol.4 No.3

The sealing cement of total hip arthroplasty is the most widely used binder in orthopedic surgery for anchoring implants to their recipient bones. Nevertheless, this latter remains a fragile material with weak mechanical properties. Inside this material cracks initiate from cavities. These cracks propagate under the effect of fatigue and lead to the failure of this binder and consequently the loosening of the prosthesis. In this context, this work consists to predict the position of cracks initiation and their propagations path using the Extended Finite Element Method (XFEM). The results show that cracks can only be initiated from a sharp edges of an ellipsoidal cavity which the ratio of the minor axis over the major axis is equal to 0.1. A maximum crack length of 19 ?m found for a cavity situated in the proximal zone position under a static loading. All cracks propagate in same(almost) way regardless of the cavity(site of initiation) position and its inclination in the proximal zone.

Fracture behavior modeling of a 3D crack emanated from bony inclusion in the cement PMMA of total hip replacement

Cherfi Mohamed,Sahli Abderahmane,Smail Benbarek 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.66 No.1

In orthopedic surgery and in particular in total hip arthroplasty, the implant fixation is carried out using a surgical cement called polymethylmethacrylat (PMMA). This cement has to insure a good adhesion between implant and bone and a good load distribution to the bone. By its fragile nature, the cement can easily break when it is subjected to a high stress gradient by presenting a craze zone in the vicinity of inclusion. The focus of this study is to analyze the effect of inclusion in some zone of cement in which the loading condition can lead to the crack opening leading to their propagation and consequently the aseptic loosening of the THR. In this study, the fracture behavior of the bone cement including a strange body (bone remain) from which the onset of a crack is supposed. The effect of loading condition, the geometry, the presence of both crack and inclusion on the stress distribution and the fracture behavior of the cement. Results show that the highest stresses are located around the sharp tip of bony inclusion. Most critical cracks are located in the middle of the cement mantle when they are subjected to one leg standing state loading during walking.

Experimental and numerical disbond localization analyses of a notched plate repaired with a CFRP patch

Sahli Abderahmane,Bouziane M. Mokhtar,Benbarek Smail,Steven F. Wayne,Liang Zhang,Bachir Bouiadjra Belabbes,Serier Boualem 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.63 No.3

Through the use of finite element analysis and acoustic emission techniques we have evaluated the interfacial failure of a carbon fiber reinforced polymer (CFRP) repair patch on a notched aluminum substrate. The repair of cracks is a very common and widely used practice in the aeronautics field to extend the life of cracked sheet metal panels. The process consists of adhesively bonding a patch that encompasses the notched site to provide additional strength, thereby increasing life and avoiding costly replacements. The mechanical strength of the bonded joint relies mainly on the bonding of the adhesive to the plate and patch stiffness. Stress concentrations at crack tips promote disbonding of the composite patch from the substrate, consequently reducing the bonded area, which makes this a critical aspect of repair effectiveness. In this paper we examine patch disbonding by calculating the influence of notch tip stress on disbond area and verify computational results with acoustic emission (AE) measurements obtained from specimens subjected to uniaxial tension. The FE results showed that disbonding first occurs between the patch and the substrate close to free edge of the patch followed by failure around the tip of the notch, both highest stress regions. Experimental results revealed that cement adhesion at the aluminum interface was the limiting factor in patch performance. The patch did not appear to strengthen the aluminum substrate when measured by stress-strain due to early stage disbonding. Analysis of the AE signals provided insight to the disbond locations and progression at the metaladhesive interface. Crack growth from the notch in the aluminum was not observed until the stress reached a critical level, an instant before final fracture, which was unaffected by the patch due to early stage disbonding. The FE model was further utilized to study the effects of patch fiber orientation and increased adhesive strength. The model revealed that the effectiveness of patch repairs is strongly dependent upon the combined interactions of adhesive bond strength and fiber orientation.

Experimental and numerical disbond localization analyses of a notched plate repaired with a CFRP patch

Abderahmane, Sahli,Mokhtar, Bouziane M.,Smail, Benbarek,Wayne, Steven F.,Zhang, Liang,Belabbes, Bachir Bouiadjra,Boualem, Serier Techno-Press 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.63 No.3

Through the use of finite element analysis and acoustic emission techniques we have evaluated the interfacial failure of a carbon fiber reinforced polymer (CFRP) repair patch on a notched aluminum substrate. The repair of cracks is a very common and widely used practice in the aeronautics field to extend the life of cracked sheet metal panels. The process consists of adhesively bonding a patch that encompasses the notched site to provide additional strength, thereby increasing life and avoiding costly replacements. The mechanical strength of the bonded joint relies mainly on the bonding of the adhesive to the plate and patch stiffness. Stress concentrations at crack tips promote disbonding of the composite patch from the substrate, consequently reducing the bonded area, which makes this a critical aspect of repair effectiveness. In this paper we examine patch disbonding by calculating the influence of notch tip stress on disbond area and verify computational results with acoustic emission (AE) measurements obtained from specimens subjected to uniaxial tension. The FE results showed that disbonding first occurs between the patch and the substrate close to free edge of the patch followed by failure around the tip of the notch, both highest stress regions. Experimental results revealed that cement adhesion at the aluminum interface was the limiting factor in patch performance. The patch did not appear to strengthen the aluminum substrate when measured by stress-strain due to early stage disbonding. Analysis of the AE signals provided insight to the disbond locations and progression at the metal-adhesive interface. Crack growth from the notch in the aluminum was not observed until the stress reached a critical level, an instant before final fracture, which was unaffected by the patch due to early stage disbonding. The FE model was further utilized to study the effects of patch fiber orientation and increased adhesive strength. The model revealed that the effectiveness of patch repairs is strongly dependent upon the combined interactions of adhesive bond strength and fiber orientation.

Geometrical parameters optimizations of scarf and double scarf bounded joint

Fekih, Sidi Mohamed,Madani, Kuider,Benbarek, Smail,Belhouari, Mohamed Techno-Press 2018 Advances in aircraft and spacecraft science Vol.5 No.3

The aim of this work is to optimize the geometrical parameters as the adhesive thickness and the beveled angle to reduce the edge effect of the scarf and V bounded joint. A finite element analysis is done to define the generated stresses in the bounded joint. The geometrical optimum is obtained using the Experimental Design Method. Results show that the double scarf (V) joint is better than the simple scarf bounded joint.