AIP Conference Proceedings 1933, 020003 (2018); https://doi.org/10.1063/1.5023937 1933, 020003
© 2018 Author(s).
Development of friction and wear full-scale testing for TKR prostheses with reliable low cost apparatus
Cite as: AIP Conference Proceedings 1933, 020003 (2018); https://doi.org/10.1063/1.5023937 Published Online: 13 February 2018
Agri Suwandi, Tresna P. Soemardi, Gandjar Kiswanto, et al.
ARTICLES YOU MAY BE INTERESTED IN
The accuracy of solid model and rapid prototype of prostheses in comparison to the digital CT image data
AIP Conference Proceedings 1817, 040014 (2017); https://doi.org/10.1063/1.4976799 Mechanical aspect analysis of dental stone grade IV material for total hip replacement component
AIP Conference Proceedings 2193, 020001 (2019); https://doi.org/10.1063/1.5139321 Hardness characteristic of dental porcelain synthesized from Indonesian natural sand AIP Conference Proceedings 1933, 020004 (2018); https://doi.org/10.1063/1.5023938
Development of Friction and Wear Full-Scale Testing for TKR Prostheses with Reliable Low Cost Apparatus
Agri Suwandi
1,a), Tresna P. Soemardi
2,b), Gandjar Kiswanto
2,c), Widjajalaksmi Kusumaningsih
3,d), and I. Gusti Agung I. G. W.
1,e)1Department of Mechanical Engineering, Faculty of Engineering, Universitas Pancasila, Srengseng Sawah Jagakarsa, Jakarta 12640, Indonesia
2Department of Mechanical Engineering, Faculty of Engineering, Universitas Indonesia, Kampus Baru UI Depok, Depok 16424, Indonesia
3Department of Medical Rehabilitation, Faculty of Medicine, Universitas Indonesia, Jl. Salemba Raya No 6, Jakarta Pusat 10430, Indonesia
a)Corresponding author: [email protected]
Abstract. Prostheses products must undergo simulation and physical testing, before clinical testing. Finite element method is a preliminary simulation for in vivo test. The method visualizes the magnitude of the compressive force and the critical location of the Total Knee Replacement (TKR) prostheses design. In vitro testing is classified as physical testing for prostheses product. The test is conducted to evaluate the potential failure of the product and the characteristics of the prostheses TKR material. Friction and wear testing are part of the in vivo test. Motion of knee joints, which results in the phenomena of extension and deflection in the femoral and tibia insert, is represented by friction and wear testing. Friction and wear tests aim to obtain an approximate lifetime in normal and extreme load patterns as characterized by the shape of the friction surface area. The lifetime estimation requires friction and wear full-scale testing equipments for TKR prostheses products. These are necessary in obtaining initial data on potential product failures and characterizing of the material based on the ASTM F2724-08 standards. Based on the testing result and statistical analysis data, the average wear rate value per year is 2.19 x 10-3 mg/MC, with a 10 % safety limit of volume and 14,400 cycles times, for 15 hours moving nonstop then the prediction of wear life of the component tibia insert is ± 10 years.
Keywords: Friction; wear; full-scale testing; TKR prostheses; reliable; low cost.
INTRODUCTION
Tribology is the science and technology of material surface that interact with one to another in the active movements, include friction phenomenon, wear and lubrication [1, 2]. In the human body Tribology phenomenon found in joints and in this study, related to the knee joint [3]. The friction and wear test were used to predict characteristics, one of the properties of the Tribology of the TKR components.It predicted the magnitude of the friction that occurs due to the motion of the kinematics and dynamics of the human body in the relevant environmental conditions. The friction and wear testing have been able to identify the factors that affect the condition of the components of the tibia (polyethylene material) for in vitro fertilization that ultimately could affect the in vivo behavior of the TKR. But according to Heintze [4], the validity of this testing method is still questioneddue to the accuracy is
merely around 80%. Friction and wear are the complex process that depends on a multitude of factors that interact [5- 7], but some of the influence of non-material which most relevant in TKR is a type of sliding motion of the components of the tibia insert (made of UHMWPE) [6] and the contact surface of the femoral component form (SS 316 L), which transfer the load to the tibia insert component [7- 9]. The cross between a sliding motion and strongly influenced the development of texture on the surface which can increase the level of wear and tear components tibia insert [6, 7].
The aim of friction and wear testing are to evaluate the potential failure of the model to optimize the design features, and improve the performance of the material used [10]. In this study, tests performed to get a pattern by contact area due to friction and wear rate of the femoral component and the tibia insert.
The friction and wear testing were conducted to get an estimate of TKR prostheses life time under the normal load contact area and the extreme reflected in surface area of wear. This work, based on existing ASTM testing methods and standards, is the development of the friction and wear full-scale testing equipment with reliable low-cost apparatus to obtain the preliminary in vitro data.
METHODS
The experimental methods of the friction and wear test conducted using semi complex motion as well as joint simulator [6], but with a simple mechanical system's motion refers ASTM standard F2724-08 about Standard Test Method for Evaluating Mobile Bearing Knee Dislocation [10]. Where these tests were utilized in the motion condition of knee flexion and extension with a pair femoral component and the tibia insert a given load. The analysis focused on the friction components of tibia insert, that continuously rubbed the femoral component. The tested products were the result of previous research on the grand project development of fast, customized prostheses design and manufacturing for TKR [11-14].
The time of testing planned for 8 hours for each sample component tibia insert with different load variants. Sample components for each load was one sample. Testing was planned with a cycle time of 14,400 cycles. Testing for 8 hours moving nonstop to limit the motion of the position 0o up to 30o moving clockwise and rotated back into neutral position. The tibia insert component was replaced after the cycle time served. The effect of friction and wear test were patterns reflected in the condition of the friction surface area by the femoral to tibia insert component, which was loaded variation. The analysis was performed in two methods, visual of the pattern on tibia insert and the statistical analysis with regression analysis.
FIGURE 1. The friction and wear test equipment.
Base Framework Side Framework Upper Framework
Spring
Handle Bracket Femoral
Adjusting Bolt & Nut Directive Bolt
Bracket Plat Tibia Insert Femoral
Component
Sliding Bracket Femoral
Femoral Component
Tibia Insert Component Tibia Insert
Component Handle
In Figure 1 shown the friction and wear test equipment were made by a user-driven movement that follows the reference standard ASTM F2724-08, which the motion was generated in the form of extension and flexion motion of the femoral component resulting friction on the tibia component inserts with a given load variation. The applied load was varyfrom 60 kg to 200 kg based on the presumption of the load used each 20 kg of load [15, 16]. The load generated from the spring that was pressed to the position of deformation.
The mechanical motion has a maximum rotation capability of up to 90o rotations. It has a spring, which can be adjusted or replaced the level of harshness. Springs used in these tools was the type of Helical Springs with the main function of the load bearing press [17]. Materials used type of spring was hard drawn carbon steel to ASTM A227 [18]. The position of the rotary tool of 30o with direction of rotation clockwise from position of 0o. The testing required a continuous motion, then the driving lever on the tool wear and tear tests provided additional or modified by using the 12 Volt DC motor type heavy duty motor with a speed of 50 RPM [19] as their motive. These were shown in Figure 2, the wear test tool with driving motor ,activator lever crankshaft as well as the power supply voltage and ampere controllers as electricity to move the DC motor.
FIGURE 2. The friction and wear full-scale testing
RESULTS AND DISCUSSION The Visual Analysis
Visualization wear test results taken by applying a digital microscope to examine the contact area generated and exposed to friction due to the apparent movement of the femoral component load on the tibia insert component. Figure 3 shown eight samples with a surface contact area of friction. The A sample until H has a load value that given as a comparison with the value of the increase in value of weight 20 kg weight from 60 kg to 200 kg. From the overall sample results, can be seen the area of friction was in the left and right niche. Because in the basin area was the contact area with the femoral component shaped curvature. In the middle, there was no pattern of friction components visible, because there is no contact of the femoral component in the middle, the insert of the tibia. In figure 3, the trend area of friction was directly proportional to a given load, which were, the greater the burden that was given, the more extensive the friction area also formed. The wider area tends to be on the left side of the area, this was possible because the influence of the lever position on the left or the presence of greater moment in the left position.
The following shown some examples of the results of the pattern on a load of 100 kg (D), 140 kg (E) and 200 kg (H). Reason for sampling the pattern on the load, because: (1) on the load 100 kg, starts to happen was a significant expansion of the friction area; (2) on the load 140 kg, taken as it was the last before the load test tool was experiencing abnormal shifting motion; as for (3). A load of 200 kg maximum load was performed in this test. The pattern generated for testing this friction and wear, were divided into two types, rough and smooth.
FIGURE 3. The results of the contact area of friction on test samples wear
(a) (b)
FIGURE 4. A rough kind of pattern of the sample E (150x zoom). (a). The right; (b). The left.
In Figure 4, the left model has a rough pattern with a broad area of 1.288 mm2 and 1.043 mm2 for the area. Figure 5 shown the sample with the greatest area of area E to a rough pattern 0.090 area mm2 and 0.809 mm2 on the left.
(a) (b)
FIGURE 5. A rough kind of pattern of the sample E (150x zoom). (a). The right; (b). The left.
Sample A (Load 60 kg)
Sample B
(Load 80 kg) Sample C
(Load 100 kg) Sample D
(Load 120 kg)
Sample E (Load 140 kg)
Sample F (Load 160 kg)
Sample G (Load 180 kg)
Sample H (Load 200 kg)
(a) (b)
FIGURE 6.A rough kind of pattern of the sample H (150x zoom). (a). The right; (b). The left.
The right model H sample has a lot of rough pattern with a broad area of 0.417 mm2(Figure 6a). While in Figure 6b, shows a rough pattern at the edge of the model with the given load 200 kg, with an area of 0.325 mm2.
TABLE 1.The friction and wear testing results data
Table 1 shown the results summary data obtained from friction and wear full-scale testing equipment. From these data, it could be looked at the greater stressreceived, then the larger the resulting pattern area as well as more and more debris generated due to rubbing. The visual results obtained data show the same thing, where the greater the given load, the value of the generated area extents will be even greater.
The Statistical analysis
In decisions often need to be made a prediction regarding the probabilities of that happening in the future with the hope the decision [20]. Then that it can be more easily performed when a relationship can be defined between the variables that annunciated. In testing this, where only regression analysis to predict the age of sharing components tibia insert with the value used was the value of variable mass of debris (m2) that were generated due to friction that femoral component and tibiainsert in relation to the value of the stress (σ) given and the value of area (A2) is generated.
Using statistical software, any data that was generated and evaluated from the wear testing was done being processed and on analysis by Regression Analysis.
As shown in Figure 7, the results of the regression equations for the calculation of the analysis that the value of P in the value of the stress (σ) = 0.009 is smaller than a level confidence value (α) = 0.05 this proves that the value of stress (σ) contribute significantly to the value of the mass of the debris (m2) at the 95% level of confidence. Value of friction areas (A2) = 0.456 was greater than the value of the trust level (α) = 0.05, it's meant friction area (A2) does not effect to the value of the mass of the debris (m2)
Left Right Total Early End Debris
A 60 588.600 62.089 3.494 3.301 6.795 18.738 18.360 0.378
B 80 784.800 82.785 3.935 3.965 7.900 18.738 18.311 0.427
C 100 981.000 103.481 4.052 4.191 8.243 18.738 18.277 0.461
D 120 1177.200 124.177 4.289 4.392 8.681 18.738 18.218 0.520
E 140 1373.400 144.873 4.372 4.168 8.540 18.738 18.169 0.569
F 160 1569.600 165.570 4.834 4.425 9.259 18.738 18.017 0.721
G 180 1765.800 186.266 4.991 4.598 9.589 18.738 17.871 0.867
H 200 1962.000 206.962 5.091 4.698 9.789 18.738 17.751 0.987
Mass, m2 (gram)
Sample Stress, σ
(MPa)
Parameter Area, A2 (mm2)
9.480 Mass, m1
(kg)
Weight, W (N)
Area, Atotal (mm2)
FIGURE 7.The results of regression analysis for mass debris (m2) than with stress (σ) and friction area (A2)
The value of R2= 94.98% of variation in outcomes mass debris (m2), while the value of the adjusted R2= 93.31%, due to the adjusted Radj2value was smaller, then the regression models have good data. The value of R2= 89.67%
prediction, because it has the value of proximity to the value of R2and the Radj2value was adjusted, then the regression model does not have a significant value increase and have a fairly good prediction capability.
FIGURE 8.Residual plots for mass debris (m2)
Figure 8 shown, the residual plots for mass debris (m2), where on the histogram indicates that there is no reasonable data on the results obtained, shown by some of the top-right of the bar away from the plot. The normal probability Plot shows a pattern of approximately linear, consistent with a normal distribution. One point in the lower left corner of the plot may be data that is not natural. While on the Residual value versus the Fit Plots show that there is a residual that get smaller values (closer to the reference line). Nevertheless, on that point are some values that fit other words, away residual value has a non-constant variable. Table 2 shown the result of the friction and wear full-scale testing.
TABLE 2.Wear rate and penetration wear test results data
The table 2 was used to get the graph of wear rate per cycle and per year cycle (million cycle) based on a given load increases. As for mass debris (m2) that affect the value of the wear rate, while the penetration rate of wear was influenced by the value of the length penetration that occur due to friction between the femoral to tibia insert components.
(a) (b)
FIGURE 9.Graphs result the friction and wear testing that occurs is proportional to the mass. (a) Cycle; (b). Million Cycle.
In Figure 9, shown graphs result the friction and wear testing that occurs is proportional to the mass, where the average value of the increase that occurred was not significant. However, there were times where the increment occurs unexpectedly, it was the result of shifting motion of an abnormal test (error), then it needs to reset the test tool. After a reset, the results remain in the range of these values, then the load was inferred that depart acceptable by this the friction and wear testing full-scale equipment was maximum 140 kg.
In in vitro studies conducted by Popoola et al. [21], for fixed bearing TKR prostheses with angular movement of the buckling of 110.7oup to 127.2oto cycle 5 x 106of the MC generates the value analysis of the wear rate on average per year was 14.2 ± 2.1 mg/MC. Whereas the results of the analysis in this study, resulting in a value of wear rate on average per year was 4.04 x 10-10mg/MC and 1,440 x 106cycles with MC or approximately one third of the cycle used by Popoola et al. [21].
A 588.600 18.738 18.360 62.089 0.378 1.06E-02 1.08E-03
B 784.800 18.738 18.311 82.785 0.427 1.41E-02 1.44E-03
C 981.000 18.738 18.277 103.481 0.461 1.77E-02 1.80E-03
D 1177.200 18.738 18.218 124.177 0.520 2.12E-02 2.16E-03
E 1373.400 18.738 18.169 144.873 0.569 2.48E-02 2.52E-03
F 1569.600 18.738 18.017 165.570 0.721 2.83E-02 2.88E-03
G 1765.800 18.738 17.871 186.266 0.867 3.18E-02 3.25E-03
H 1962.000 18.738 17.751 206.962 0.987 3.54E-02 3.61E-03
A 588.600 18.738 18.360 62.089 0.0015 1.04E-07 1.04E-09
B 784.800 18.738 18.311 82.785 0.0018 1.25E-07 1.25E-09
C 981.000 18.738 18.277 103.481 0.0020 1.39E-07 1.39E-09
D 1177.200 18.738 18.218 124.177 0.0022 1.53E-07 1.53E-09
E 1373.400 18.738 18.169 144.873 0.0024 1.67E-07 1.67E-09
F 1569.600 18.738 18.017 165.570 0.0033 2.29E-07 2.29E-09
G 1765.800 18.738 17.871 186.266 0.0039 2.71E-07 2.71E-09
H 1962.000 18.738 17.751 206.962 0.0074 5.14E-07 5.14E-09
Wear Rate
Cycle (C) Million Cycle (MC)
Mass of Debris , ms
(gram)
Wear Rate, WR (mg/C)
Wear Rate, WR (mg/MC or
mg/year)
Penetration Wear Rate, WR (mm/MC
or mm/year) Sample Weight, W
(N)
9.480 14400 1.44E+06
Stress, σ (MPa)
Cycle Time Penetration Wear
Length Penetration
(mm)
Penetration Wear Rate, WR (mm/C) End Mass
, m2 (gram)
Friction Area, Atotal
(mm2) Early Mass
, m1 (gram) Early Mass , m1 (gram)
End Mass
, m2 (gram) Cycle (C) Million
Cycle (MC)
9.480 14400 1.44E+06
Stress, σ (MPa)
Cycle Time Friction
Area, Atotal
(mm2) Sample Weight, W
(N)
In addition to the wear rate, this test also provided analytically of the penetration depth of friction and wear testing.
In Figure 10. showed graph depth of friction and wear testing that occurs with respect to a given mass, where the average value increased significantly. This indicated that the given mass influenced the wear penetration rate. The average depth penetration rate, resulting in this study was 2.97 x 10-9mm/MC. These valueswasstill lower than the value of the depth penetration rate of in vivo results from Currier et al. [22], which was 0.023 mm/MC using model TKR fixed bearing.
(a) (b)
FIGURE 10.Graphs result depth of friction and wear testing that occurs is proportional to the mass. (a) Cycle; (b). Million Cycle.
Figure 11. shown a comparison chart showing area of friction with the number of cycle failure, where the larger the value of the cycle, then the smaller the area of friction was happening. This was affected by the reduced thickness of the surface of a component due to the phenomenon of friction that occurs.
FIGURE 11.Graph surface area of friction versus cycle value
CONCLUSION
The conclusion of experimental friction and wear full-scale testing: (1). Based on the digital microscope observation, that the friction area was on the left and right area, which is an area of contact with the femoral component, was shaped curvature. Meanwhile, in the middle area of the components can be virtually no friction area formed, because there was no contact at the center of the femoral component; (2). Trends contact area of the friction was proportional to the applied load, the greater the load given, then more knowledgeable friction area formed, this was consistent with Currier et al. [22]; (3). The result of the wear test, the wear rate value per year is 2.19 x 10-3mg/MC and the average penetration rate is 1.94 x 10-9mm/MC; (4). Base for the statistical analysis of Regression (Regression Analysis) and 95% confidence level (degree of meaning) the value of stress (σ) contribute significantly to the value
0.000 5.000 10.000 15.000 20.000 25.000
0.0E+00 1.4E+01 1.4E+02 1.4E+03 1.4E+04 Friction Area, Atotal(mm2)
Number of Cycle Failure, N (Cycle)
A = 60 kg B = 80 kg C = 100 kg D = 120 kg E = 140 kg F = 160 kg G = 180 kg H = 200 kg
of the mass of the debris (m2) but does not for the value of friction area; (5) Using the statistical analysis its can be predicted ware value safe rate for normal weight of adult male or female (if user data taken ± 50 years old with an average weight of 70 kg) is 2.80 x10-7 mm/MC; (6) Using a safe margin value of wear from initial 10% volume [22]
obtained from the test result that the maximum safe load wear is 100 kg with the percentage of wear volume 8.98%;
and (7) Based on the testing results and statistical analysis data, the prediction of wear life of the component tibia insert is ± 10 years.
REFERENCES
1. Departemen Pendidikan Nasional, Pusat Bahasa Indonesia, Kamus besar bahasa Indonesia Pusat Bahasa, (Gramedia Pustaka Utama, Jakarta, 2008).
2. T. M. Grupp, R. K. Miehlke, M. Hintner and J. Schwiesau, J. ASTM Inter 8, 204-217 (2011).
3. L. S. Pinchuk, V. I. Nikolaev, E. A. Tsvetkova and V. A. Goldade, Tribology and Biophysics of Artificial Joints (Elsevier B.V, Amsterdam, 2006).
4. S. D. Heintze, Dent. Mat 22, 712–734 (2006).
5. B. Denkena, J. Kohler, A. Turger, T. Correa and C. Hurschler, Proced. CIRP 5, 179 – 184 (2013).
6. E. W. Patten, D. V. Citters, M. D. Ries and L. A. Pruitt, Wear 304, 60–66 (2013).
7. H. M. J. McEwen, P. I. Barnett, C. J. Bel, R. Farrar, D. D. Auger, M. H. Stone and J. Fisher, J. Biomech. 38, 357–365 (2005).
8. H. J. Lundberg, K. C. Foucher and M. A. Wimmer, J. Biomech 42, 541–545 (2009).
9. J. K. L. Lee, K. Maruthainar, N. Wardle, F. Haddad and G. W. Blunn, The Knee 16, 269–274 (2009).
10. P. S. Walker and H. Haider, J ASTM Intern 9, 1-14 (2012).
11. A. Suwandi, G. Kiswanto, T. P. Soemardi and W. Kusumaningsih, Adv. Mat. Res 980, 243-247 (2014).
12. T. P. Soemardi, A. Suwandi, G. Kiswanto and W. Kusumaningsih, ARPN J. Eng. Appli. Sci 11, 10023-10027 (2016)
13. T. P. Soemardi, A. Suwandi, G. Kiswanto and W. Kusumaningsih, Inter. J. Technol, 1035-1044 (2016).
14. A. Suwandi, G. Kiswanto, W. Kusumaningsih and T. P. Soemardi, "The accuracy of solid model and rapid prototype of prostheses in comparison to the digital CT image data," in AIP Conference Proceedings (The First International Symposium of Biomedical Engineering Conference Proceeding, Depok, 2017)
15. S. Lampman, Ed. ASM Handbook: Fatigue and Fracture 19, (1996).
16. S. Chowdhury and N. Kumar. J. Rehab. Robotics 1, 93-98 (2013).
17. R. L. Mott. Machine Element in Mechanical Design (Pearson Prentice Hall, Upper Saddle River, 2004).
18. S. R. Schmid, B. J. Hamrock and B. O. Jacobson. Fundamentals of Machine Elements, SI Version, 3nd ed (CRC Press-Taylor & Francis Group, New York, 2014).
L. D. Angibaud, A. Burstein, W. B. Balcom and G. J. Miller, J. ASTM Inter 8, 195-203 (2011).
20. Harinaldi, Prinsip-Prinsip Statistik untuk Teknik dan Sains (Erlangga, Jakarta, 2005).
21. O. Popoola, N. Yu and G. Scuderi, J. ASTM Inter 8, 133-145 (2011).
22. J. H. Currier, E. C. Porter, M. B. Mayor, J. P. Collier and D. W. V. Citters, J. ASTM Inter 8,156-171 (2011).
