Initial Assessments of a Handheld Indentation Probe's Correlation with Cancellous Bone Density, Stiffness and Strength: An Objective Alternative to 'Thumb Testing'

2021 ◽  
Author(s):  
Jacob Reeves ◽  
Tom Vanasse ◽  
Christopher Roche ◽  
Kenneth J. Faber ◽  
G. Daniel G. Langohr
Keyword(s):  
Compressive Strength ◽  
Bone Density ◽  
Impact Energy ◽  
Material Properties ◽  
Indentation Depth ◽  
Strong Correlations ◽  
Bone Properties ◽  
Depth Scale ◽  
Correlation Strength ◽  
Metaphyseal Bone

Abstract During shoulder arthroplasty, surgeons must select the optimal implant for each patient. The metaphyseal bone properties affect this decision; however, the typical resection 'thumb test' lacks objectivity. The purposes of this investigation were: to determine the correlation strength between the indentation depth of a handheld mechanism and the density, compressive strength and modulus of a bone surrogate; as well as to assess how changing the indenter tip shape and impact energy may affect the correlation strengths. A spring-loaded indenter was developed. Four tip shapes (needle, tapered, flat and radiused cylinders) and four spring energies (0.13J-0.76J) were assessed by indenting five cellular foam bone surrogates of varying density. The indentation depth was measured and correlated with apparent density, compressive strength and modulus. Indentation depth plateaued as the bone surrogate's material properties increased, particularly for indentation tips with larger footprints and the 0.13J spring. All tip shapes produced strong (R2≥0.7) power-law relationships between the indentation depth metric and the bone surrogate's material properties (density: 0.70 ≤ R2 ≤ 0.95, strength: 0.75 ≤ R2 ≤ 0.97, modulus: 0.70 ≤ R2 ≤ 0.93); though use of the needle tip yielded the widest indentation depth scale. These strong correlations suggest that a handheld indenter may provide objective intraoperative evidence of cancellous material properties. Further investigations are warranted to study indenter tip shape and spring energy in human tissue; though the needle tip with spring energy between 0.30J and 0.76J seems the most promising.

scholarly journals Identifying Spatial and Temporal Variations in Concrete Bridges with Ground Penetrating Radar Attributes

2021 ◽  
Vol 13 (9) ◽  
pp. 1846
Author(s):  
Vivek Kumar ◽  
Isabel M. Morris ◽  
Santiago A. Lopez ◽  
Branko Glisic
Keyword(s):  
Compressive Strength ◽  
Ground Penetrating Radar ◽  
Material Properties ◽  
Temporal Variations ◽  
Concrete Bridges ◽  
Spatial And Temporal Variation ◽  
Reflected Waves ◽  
Ground Penetrating ◽  
Over Time

Estimating variations in material properties over space and time is essential for the purposes of structural health monitoring (SHM), mandated inspection, and insurance of civil infrastructure. Properties such as compressive strength evolve over time and are reflective of the overall condition of the aging infrastructure. Concrete structures pose an additional challenge due to the inherent spatial variability of material properties over large length scales. In recent years, nondestructive approaches such as rebound hammer and ultrasonic velocity have been used to determine the in situ material properties of concrete with a focus on the compressive strength. However, these methods require personnel expertise, careful data collection, and high investment. This paper presents a novel approach using ground penetrating radar (GPR) to estimate the variability of in situ material properties over time and space for assessment of concrete bridges. The results show that attributes (or features) of the GPR data such as raw average amplitudes can be used to identify differences in compressive strength across the deck of a concrete bridge. Attributes such as instantaneous amplitudes and intensity of reflected waves are useful in predicting the material properties such as compressive strength, porosity, and density. For compressive strength, one alternative approach of the Maturity Index (MI) was used to estimate the present values and compare with GPR estimated values. The results show that GPR attributes could be successfully used for identifying spatial and temporal variation of concrete properties. Finally, discussions are presented regarding their suitability and limitations for field applications.

Modeling and analysis of impact energy absorber by using ls dyna

2015 ◽  
Vol 12 (1) ◽  
pp. 23-28 ◽  
Author(s):  
Adik Yadao ◽  
R. S. Hingole
Keyword(s):  
Impact Energy ◽  
Material Properties ◽  
Research Work ◽  
Cad Model ◽  
Post Processing ◽  
Passenger Compartment ◽  
Efficient Manner ◽  
Energy Absorber ◽  
Modeling And Analysis ◽  
Energy Absorbing

Today’s car is one of the most important things in everyone’s life .Every person wants to have his or her own car but the question that arises in each buyer’s mind is whether the vehicle is safe enough to spend so much of money so it is the responsibility of an mechanical engineer to make the vehical comfortable and at the Same time safer. Now a days automakers are coming with various energy absorbing devices such as crush box, door beams etc. this energy absorbing device s prove to be very useful in reducing the amount force that is being transmitted to the occupant. In this we are using impact energy absorber in efficient manner as compare to earlier. The various steps involved in this project starting from developing the cad model of this inner impact energy absorber using the CAD software CATIA V5 R19. Then pre-processing is carried out in HYPERMESH 11.0 which includes assigning material, properties, boundary conditions such as contacts, constraints etc. LS-DYNA971 is used as a solver and LS-POST is used for the post processing and results obtained are compared to the standards. By carrying out this idea it has been observed that there is a considerable amount of energy that is being absorbed by this energy-absorbing device. Along with this energy absorption, the intrusion in passenger compartment is also reduced by considerable amount. So for safer and comfortable car with inner impact energy absorber is one of the best options available. This will get implement by this research work.

Investigation of Point Load Index Using Novel Discrete Based Model

2016 ◽  
Vol 846 ◽  
pp. 348-353
Author(s):  
Somayeh Behraftar ◽  
Joshua Heslin ◽  
S. Galindo Torres ◽  
Alexander Scheuermann
Keyword(s):  
Compressive Strength ◽  
Material Properties ◽  
Mechanical Model ◽  
Rock Type ◽  
Correlation Factor ◽  
Point Load ◽  
Load Test ◽  
Point Load Index ◽  
Bonded Particles ◽  
The One

In this study, a micro-mechanical model is developed to study the correlation of the point load index in rocks with uniaxial compressive strength (UCS) tests. The model is represented by an array of bonded particles simulated by a novel discrete based model, which was introduced by the authors previously. The point load test (PLT) is performed in the field on rock samples to classify and estimate the UCS of a rock type via the index-to-strength correlation factor k. Numerical analyses, such as the one presented in this work, will serve to close the knowledge gap concerning the correlation between k, UCS and other material properties of rocks.

Effects of Carbon Fiber Hybridization on the Compressive Strength of Glass-Carbon/Epoxy Hybrid Composite Pipes before and after Low Velocity Impact

2019 ◽  
Vol 796 ◽  
pp. 30-37 ◽  
Author(s):  
Naseer H. Farhood ◽  
Saravanan Karuppanan ◽  
Hamdan Haji Ya ◽  
Mark Ovinis
Keyword(s):  
Compressive Strength ◽  
Carbon Fiber ◽  
Impact Energy ◽  
Failure Modes ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Content Ratio ◽  
Before And After ◽  
Glass Carbon ◽  
Composite Pipes

In this paper, the effect of carbon fiber hybridization on the compressive strength of glass-carbon/epoxy hybrid filament wound pipes before and after low velocity impact was investigated experimentally. Specifically, the effects of different stacking sequence and fiber content ratio on the compression and compression after impact (CAI) behavior of hybrid glass-carbon fiber reinforced polymer pipes were analyzed. Hybrid composite pipes composed of eight layers of / reinforced with thin HDPE liner were manufactured utilizing filament winding technique. A series of axial compressive tests were carried out on the composite pipes for the non-impacted and impacted specimens under 100 J of impact energy. Residual compressive strength, damage tolerance and failure modes were examined and analyzed for different pipe configurations, before and after the impact. The failure modes of non-impacted and impacted composite pipes under compressive loading were analyzed visually. The results show that, under the same conditions of impact energy, specimens with alternative fibers exhibited better impact resistance regardless of fiber content ratio. Moreover, carbon fiber reinforced epoxy specimens exhibited the worst impact damage tolerance for a given impact energy level although having the highest compressive strength before impact among the samples, with the highest percentage reduction of 62% in residual compressive force after impact.

scholarly journals The effect of zeolite addition on parameters of concrete containing recycled ceramic aggregate

2018 ◽  
Vol 45 ◽  
pp. 00116
Author(s):  
Jacek Szulej ◽  
Paweł Ogrodnik
Keyword(s):  
Compressive Strength ◽  
Material Properties ◽  
Frost Resistance ◽  
Environmentally Friendly ◽  
Concrete Material ◽  
Dominant Component ◽  
Concrete Mix ◽  
Aluminous Cement ◽  
Compressive Strength Of Concrete ◽  
Zeolite Tuff

In the paper it was decided to recognize the material characteristics of concrete based on ceramic aggregate, aluminous cement with the addition of zeolite (5%, 10%, 15%) and air entraining admixture. Aggregate crushed to 2 fractions was used for designing the concrete mix : 0-4 mm, and 4-8 mm. The research involved the use of clinoptilolite derived from the zeolite tuff deposit at Sokyrnytsya (Transcarpathia, Ukraine). The dominant component in the zeolite is clinoptilolite in an amount of about 75%. The research carried out by the authors showed that the addition of zeolite, among others, increases the compressive strength of concrete, significantly improves the frost resistance, which in the case of using only aluminous cement is very low. The obtained results confirm the possibility of using the above-mentioned components, which improve the concrete material properties and are environmentally friendly.

Compressive Strength of CCF300/QY8911 Composite Laminates with LVI Damage

2012 ◽  
Vol 583 ◽  
pp. 203-206
Author(s):  
Hai Ming Hong ◽  
Ming Li ◽  
Jian Yu Zhang ◽  
Yi Ning Zhang
Keyword(s):  
Compressive Strength ◽  
Impact Energy ◽  
Composite Laminates ◽  
Inflection Point ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Damage Area ◽  
Compressive Performance ◽  
The Impact ◽  
Dent Depth

A series of low-velocity impact tests and residual compressive strength tests after impacts on CCF300/QY8911 composite materials were carried out to study the mechanism of compression failure of the laminates after low-velocity impact. The curves of impact energy verse dent depth and impact energy verse the damage area was obtained. And the residual compressive strength and stiffness after impact verse damage parameters were analyzed. The results showed that when the impact energy exceeded the inflection point, as the impact energy increased, the dent depth on the impacted surface of the laminates notably increased while the damage area of the internal layers merely increased slowly. If the impact energy was continued to increase, the expansion of the laminates' internal damage mainly consisted of fiber breaks. The main reason for the decrease in compressive performance of composite laminates was inside delamination between layers, while in the case in which impact energy exceeded the inflection point, there were no obvious changes in delamination damage area for different energy, so the residual compressive performance kept almost stable.

scholarly journals Effect of Cavity Design on the Strength of Direct Posterior Composite Restorations: An Empirical and FEM Analysis

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
V. Susila Anand ◽  
C. Kavitha ◽  
C. V. Subbarao
Keyword(s):  
Finite Element ◽  
Stainless Steel ◽  
Compressive Strength ◽  
Material Properties ◽  
Null Hypothesis ◽  
Fem Analysis ◽  
Empirical Testing ◽  
Composite Restorations ◽  
Concave Shape ◽  
Cavity Design

The aim of the present study was to verify the hypothesis that cavity design does not affect the strength of direct composite restorations as do material properties. Finite element modeling (FEM) and empirical testing were done for two cavity designs: a box shape (cube) and a concave shape (U). Two microhybrid composites were used to prepare the samples with the help of split stainless steel moulds. Compressive strength was tested. The results were statistically analyzed. Both FEA and empirical testing were complementary to each other in that the concave shape showed a significantly higher strength than box. Material properties affected the values only when box shape was used. The null hypothesis is thus rejected, and it is concluded that design significantly affects the strength of direct composite restorations.

scholarly journals Degradation of Roller-Compacted Concrete Subjected to Freeze-Thaw Cycles and Immersion in Potassium Acetate Solution

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Wuman Zhang ◽  
Jingsong Zhang ◽  
Shuhang Chen ◽  
Sheng Gong
Keyword(s):  
Mechanical Properties ◽  
Weight Loss ◽  
Compressive Strength ◽  
Impact Energy ◽  
Impact Test ◽  
Potassium Acetate ◽  
Acetate Solution ◽  
Freeze Thaw ◽  
Roller Compacted Concrete ◽  
The Impact

Two sets of roller-compacted concrete (RCC) samples cured for 28 days were subjected to freeze-thaw (F-T) cycles and immersion in laboratory conditions. F-T cycles in water and water-potassium acetate solution (50% by weight) were carried out and followed by the flexural impact test. The weight loss, the dynamic elastic modulus (Ed), the mechanical properties, and the residual strain of RCC were measured. The impact energy was calculated based on the final number of the impact test. The results show that the effect of F-T cycles in KAc solution on the weight loss and Ed of RCC is slight. Ed, the compressive strength, and the flexural strength of RCC with 250 F-T cycles in KAc solution decrease by 3.8%, 23%, and 36%, respectively. The content (by weight) of K+ at the same depth of RCC specimens increases with the increase of F-T cycles. The impact energy of RCC specimens subjected to 250 F-T cycles in KAc solution decreases by nearly 30%. Microcracks occur and increase with the increase of F-T cycles in KAc solution. The compressive strength of RCC immersed in KAc solution decreases by 18.8% and 32.8% after 6 and 12 months. More attention should be paid to using KAc in practical engineering because both the freeze-thaw cycles and the complete immersion in KAc solution damage the mechanical properties of RCC.

scholarly journals Pasta packaging with bio-based barrier to prevent insect infestation

2020 ◽  
Author(s):  
Urška Vrabič Brodnjak ◽  
◽  
Pasquale Trematerra ◽  
Keyword(s):  
Compressive Strength ◽  
Material Properties ◽  
Water Resistance ◽  
Packaging Material ◽  
Sitophilus Zeamais ◽  
Polyethylene Film ◽  
Insect Infestation ◽  
Maize Weevil ◽  
Different Types ◽  
Mechanical Overload

The results of the infestation by maize weevil, Sitophilus zeamais (Coleoptera, Curculionidae) in various packages filled with pasta are presented. Three different types of packaging were used, i.e. two paper tubes (a novel one laminated with bio-based polyethylene and one without lamination) and a commercially available polypropylene pillow pouch packaging. Material properties such as moisture and water resistance and compressive strength were analysed. The results obtained showed that adult maize weevils revealed significant preferences to penetrate the pasta packaging through the already existing holes that were present in the polypropylene packaging, whereas no infestation was observed inside the paper tube packaging. The study showed that the shape and construction, e.g. tube packaging with an innovative bio-polyethylene film, is very effective against insect infestation and mechanical overload.

scholarly journals Determination of Mechanical Properties of Slurry Infiltrated Steel Fiber Concrete Using Fly Ash and Metakaolin

2018 ◽  
Vol 7 (4.5) ◽  
pp. 262
Author(s):  
Shelorkar A.P ◽  
Jadhao P.D
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Fly Ash ◽  
Impact Energy ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Strength Properties ◽  
Steel Fibers ◽  
Flexural Tensile Strength ◽  
Fiber Concrete

This paper reports on a wide-ranging study on the properties of slurry infiltrated fiber concrete containing fly ash, Metakaolin, and hook ended steel fibers. Properties studied include workability of fresh slurry infiltrated fiber concrete, and compressive strength, flexural tensile strength, splitting tensile strength, dynamic elasticity modulus, impact energy of hardened slurry infiltrated fiber concrete. Fly ash and Metakaolin content used was 0%, 2.5%, 5.0%, 7.5% and 10% in mass basis, and hook ended steel fibers volume fraction was 0%, 2.0%, 3.0% and 4.0% in volume basis. The laboratory results showed that steel fiber addition, either into control concrete or fly ash, Metakaolin blend slurry infiltrated fiber concrete; improve the tensile strength properties, flexural strength, impact energy and modulus of elasticity. In this experimental study, compressive strength improvement ratio is 33.60%, and Structural efficiency is 9.50 % higher in slurry infiltrated fiber-concrete with Metakaolin as compared with fly ash based slurry infiltrated fiber concrete at the 4% replacement ratio of hook ended steel fibers by volume.  

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