Lower Strain Energy Research Articles

Topology optimization for submerged buoyant structures

ABSTRACTThis paper presents an evolutionary structural topology optimization method for the design of completely submerged buoyant modules with design-dependent fluid pressure loading. This type of structure is used to support offshore rig installation and pipeline transportation at all water depths. The proposed optimization method seeks to identify the buoy design that has the highest stiffness, allowing it to withstand deepwater pressure, uses the least material and has a minimum prescribed buoyancy. Laplace's equation is used to simulate underwater fluid pressure, and a polymer buoyancy module is considered to be linearly elastic. Both domains are solved with the finite element method. Using an extended bi-directional evolutionary structural optimization (BESO) method, the design-dependent pressure loads are modelled in a straightforward manner without any need for pressure surface parametrization. A new buoyancy inequality constraint sets a minimum required buoyancy effect, measured by the joint volume of the structure and its interior voids. Solid elements with low strain energy are iteratively removed from the initial design domain until a certain prescribed volume fraction. A test case is described to validate the optimization problem, and a buoy design problem is used to explore the features of the proposed method.

Heterogeneous filament network formation by myosin light chain isoforms effects on contractile energy output of single cardiomyocytes derived from human induced pluripotent stem cells.

Cardiomyocytes derived from human induced pluripotent stem cells (hiPSC-CMs) are expected to play an important role in heart therapies, in which hiPSC-CMs should generate sufficient contractile force to pump blood. However, recent studies have shown that the contractility of myocardial mimics composed of hiPSC-CMs is lower than that of adult human myocardium. To examine the mechanism by which contractile force output of hiPSC-CMs is weakened, we measured the contractile force of single hiPSC-CMs and observed the fibrous distribution of myosin II regulatory light chain (MRLC) of cardiac (contributes to beating) and non-cardiac (does not contribute to beating) isoforms. Single hiPSC-CMs were cultured on an extracellular matrix gel, and the contractile force and strain energy exerted on the gel were measured. Strain energy was not uniform between cells and ranged from 0.2 to 5.8 pJ. The combination of contractile force measurement and immunofluorescent microscopy for MRLC isoforms showed that cells with higher strain energy expressed the weakened non-cardiac myosin II fibers compared to those of cells with lower strain energy. Observation of cardiac and non-cardiac MRLC showed that the MRLC isoforms formed heterogeneous filament networks. These results suggest that strain energy output from single hiPSC-CMs depends both cardiac and non-cardiac myosin fibers, which prevent deformation of the cell body.

Impact of Different Boundary Conditions on the Response of Glare Fiber-Metal Laminates under Lateral Indentation

In this paper, a finite element modelling procedure is implemented in order to predict the static load-indentation curves and the defection shape of simply supported circular GLARE fibre-metal laminates subjected to lateral indentation by a hemispherical indentor. ANSYS software is used and a non-linear analysis is employed with geometric and material non-linearities for FEM calculations. The finite element modelling procedure is applied to GLARE 2–2/1–0.3 and to GLARE 3–3/2–0.4 simply supported circular plates with various diameters. It is found that the simply supported circular GLARE plates deform axisymmetrically from the beginning of the indentation process up to the point of their first failure due to glass-epoxy tensile fracture. By comparison of the obtained load-indentation curves to corresponding previously published load-indentation curves of clamped circular GLARE plates, the effect of the different boundary conditions on their lateral indentation response is studied. Furthermore, the strain energy-indentation curves of the considered circular GLARE 2 and GLARE 3 plates with simply supported and clamped boundaries are calculated and compared. It is found that the simply supported GLARE plates have reduced stiffness and demonstrate an increased first failure defection due to glass-epoxy tensile fracture versus the clamped GLARE plates, whereas the first failure load is not significantly affected by the different boundary conditions. It is also found that for the same lateral indentation, simply supported GLARE plates absorb lower strain energy levels than clamped GLARE plates. Referring to a specific lateral indentation level, the influence of the different boundary support on the corresponding indentation load and the absorbed strain energy is strong and can reach a deviation level of 45 % between the two support types. To our knowledge, a research concerning the response of simply supported GLARE plates under lateral indentation has not been published elsewhere.

Influence of the twin microstructure on the mechanical properties in magnetic shape memory alloys

The microstructure evolution, i.e. reorientation of martensite variants, is an important deformation mechanism in shape-memory alloys. This microstructure evolution occurs by the motion of twin boundaries and the nucleation and annihilation of twins in the hierarchical microstructure. An appropriate discrete disclination model for the description of the internal elastic fields and microstructure evolution is introduced for representative volume elements. The model is applied to an experimentally characterized microstructure, i.e. conjugation boundary, and the predicted mechanical response is verified by comparison to experimental measurements. The influence of the twin microstructure on the homogenized stress-strain curve is studied. It is found that regular twinned microstructures have a low strain energy and a high resistance against deformation. These simulations also reason the origin of the microstructural stability of conjugation boundaries.

Crystal orbital studies on the 1D silic-diyne nanoribbons and nanotubes

This work presents crystal orbital studies on novel one-dimensional (1D) nanoscale materials derived from a Si-diyne sheet, based on the density functional theory. The two-dimensional (2D) Si-diyne layer is observed to be carbo-merized silicene, with a similar structure to graphdiyne. The 2D Si-diyne and its 1D ribbons and tubes, of different size and chirality, have been addressed systematically. The low dimensional Si-diyne materials studied exhibit relatively high stability, according to phonon-frequency calculations and molecular dynamics simulations. With comparable diameters, the Si-diyne tubes have lower strain energies than silicene and silicon carbide nanotubes. The Si-diyne layer and its 1D derivatives are all semiconductors, regardless of the size and chirality of the strips and tubes. In addition, the band gaps of the 1D Si-diyne nanoribbons and nanotubes with different chirality, always monotonically decrease as their sizes increases. A quantitative relationship between the band gap and the size of the ribbons and tubes was obtained. The mobility of charge carriers for the 1D Si-diyne structures was also investigated. It was found that both hole and electron mobility of the ribbons and tubes exhibit linear increase with increasing size. The electrons have greater mobility than the holes for each strip and tube. In addition, the mechanical properties of the Si-diyne nanostructures were also investigated by calculation of the Young’s modulus and the Poisson’s ratio.

Topology optimization of strut-and-tie models in steel plate shear walls

Since 1970, the steel plate shear wall is regarded as the first choice among latest load resisting systems and employed in several important and modern buildings. In the early and during the 1970s, the steel plate shear walls were used in modern buildings in Japan and United States to improve the seismic behavior of structures. It can be concluded from existing researches that the steel plate shear walls have considerable strength and stiffness in comparison with other systems. In order to find the optimum size that minimizes structure’s weight under the applied load and also fulfilling the structural requirements and restrictions optimization is required. In this study, tracing the shear wall elements with the lowest strain energy through using the topology optimization based on finite element method and removing them according to particular mechanism is investigated. This procedure gives us the optimized shape of steel plate shear wall. For this purpose, a steel plate shear wall is modeled in Abaqus to obtain its force-displacement curve and subsequently the force-displacement relationship is acquired using virtual work method and MATLAB programming.

Completely recyclable biopolymers with linear and cyclic topologies via ring-opening polymerization of γ-butyrolactone.

Ring-opening polymerization (ROP) is a powerful synthetic methodology for the chemical synthesis of technologically important biodegradable aliphatic polyesters from cyclic esters or lactones. However, the bioderived five-membered γ-butyrolactone (γ-BL) is commonly referred as 'non-polymerizable' because of its low strain energy. The chemical synthesis of poly(γ-butyrolactone) (PγBL) through the ROP process has been realized only under ultrahigh pressure (20,000 atm, 160 °C) and only produces oligomers. Here we report that the ROP of γ-BL can, with a suitable catalyst, proceed smoothly to high conversions (90%) under ambient pressure to produce PγBL materials with a number-average molecular weight up to 30 kg mol(-1) and with controlled linear and/or cyclic topologies. Remarkably, both linear and cyclic PγBLs can be recycled back into the monomer in quantitative yield by simply heating the bulk materials at 220 °C (linear polymer) or 300 °C (cyclic polymer) for one hour, which thereby demonstrates the complete recyclability of PγBL.

Room Temperature Deformation Mechanisms of Alumina Particles Observed from In Situ Micro-compression and Atomistic Simulations

Aerosol deposition (AD) is a solid-state deposition technology that has been developed to fabricate ceramic coatings nominally at room temperature. Sub-micron ceramic particles accelerated by pressurized gas impact, deform, and consolidate on substrates under vacuum. Ceramic particle consolidation in AD coatings is highly dependent on particle deformation and bonding; these behaviors are not well understood. In this work, atomistic simulations and in situ micro-compressions in the scanning electron microscope, and the transmission electron microscope (TEM) were utilized to investigate fundamental mechanisms responsible for plastic deformation/fracture of particles under applied compression. Results showed that highly defective micron-sized alumina particles, initially containing numerous dislocations or a grain boundary, exhibited no observable shape change before fracture/fragmentation. Simulations and experimental results indicated that particles containing a grain boundary only accommodate low strain energy per unit volume before crack nucleation and propagation. In contrast, nearly defect-free, sub-micron, single crystal alumina particles exhibited plastic deformation and fracture without fragmentation. Dislocation nucleation/motion, significant plastic deformation, and shape change were observed. Simulation and TEM in situ micro-compression results indicated that nearly defect-free particles accommodate high strain energy per unit volume associated with dislocation plasticity before fracture. The identified deformation mechanisms provide insight into feedstock design for AD.

Thermal cycling behavior of EB-PVD TBCs on CVD platinum modified aluminide coatings

Thermal barrier coating systems (TBCs) including of chemical vapor deposited (Ni, Pt)Al bond coat with grit blasting process and electron beam physical vapor deposited Y2O3-stabilized-ZrO2 (YSZ) ceramic coating were investigated. The phase structures, surface and cross-sectional morphologies, cyclic oxidation behaviors and residual stresses of the TBCs were studied in detail. It was found that the fracture path traverses through the ceramic coating to TGO interface, as well as at the TGO to bond coat interface is obviously detected. The change in fracture plane occurs at grain boundaries. The ridge top spallation leads to separate of sufficient size to result in unstable fracture driven by the strain energy stored in the TGO. The bond coat can undergo a volume increase upon oxidation, so that a cavity, enlarged strictly by oxidation would be full to overflowing with TGO layer. The spalled location of the TBCs probably occurs either at the interface of TGO layer and bond coat or inside of TGO layer. The lower strain energy release rate within TGO layer during thermal cycling is beneficial to prolong of TBCs life. The lower is the compressive stress within TGO layer, the longer is the lifetime of TBCs.

A novel inhibitor of Plasmodium falciparum spermidine synthase: a twist in the tail.

BackgroundPlasmodium falciparum is the most pathogenic of the human malaria parasite species and a major cause of death in Africa. It’s resistance to most of the current drugs accentuates the pressing need for new chemotherapies. Polyamine metabolism of the parasite is distinct from the human pathway making it an attractive target for chemotherapeutic development. Plasmodium falciparum spermidine synthase (PfSpdS) catalyzes the synthesis of spermidine and spermine. It is a major polyamine flux-determining enzyme and spermidine is a prerequisite for the post-translational activation of P. falciparum eukaryotic translation initiation factor 5A (elF5A). The most potent inhibitors of eukaryotic SpdS’s are not specific for PfSpdS.Methods‘Dynamic’ receptor-based pharmacophore models were generated from published crystal structures of SpdS with different ligands. This approach takes into account the inherent flexibility of the active site, which reduces the entropic penalties associated with ligand binding. Four dynamic pharmacophore models were developed and two inhibitors, (1R,4R)-(N1-(3-aminopropyl)-trans-cyclohexane-1,4-diamine (compound 8) and an analogue, N-(3-aminopropyl)-cyclohexylamine (compound 9), were identified.ResultsA crystal structure containing compound 8 was solved and confirmed the in silico prediction that its aminopropyl chain traverses the catalytic centre in the presence of the byproduct of catalysis, 5′-methylthioadenosine. The IC50 value of compound 9 is in the same range as that of the most potent inhibitors of PfSpdS, S-adenosyl-1,8-diamino-3-thio-octane (AdoDATO) and 4MCHA and 100-fold lower than that of compound 8. Compound 9 was originally identified as a mammalian spermine synthase inhibitor and does not inhibit mammalian SpdS. This implied that these two compounds bind in an orientation where their aminopropyl chains face the putrescine binding site in the presence of the substrate, decarboxylated S-adenosylmethionine. The higher binding affinity and lower receptor strain energy of compound 9 compared to compound 8 in the reversed orientation explained their different IC50 values.ConclusionThe specific inhibition of PfSpdS by compound 9 is enabled by its binding in the additional cavity normally occupied by spermidine when spermine is synthesized. This is the first time that a spermine synthase inhibitor is shown to inhibit PfSpdS, which provides new avenues to explore for the development of novel inhibitors of PfSpdS.Electronic supplementary materialThe online version of this article (doi:10.1186/s12936-015-0572-z) contains supplementary material, which is available to authorized users.

H2Ti5O11·H2O nanorod arrays formed on a Ti surface via a hybrid technique of microarc oxidation and chemical treatment

H2Ti5O11·H2O nanorod arrays deposited on a titanium (Ti) surface have been fabricated via a hybrid technique of microarc oxidation (MAO) and chemical treatment. After the MAO treatment, an amorphous phase composed porous coating containing Ca, P, Si and Na elements was formed on the Ti surface. At the beginning of the chemical treatment, the elements of Ca, P, Si and Ti dissolved from the MAO coating into the solution. With a prolonged treatment time, nanorod arrays with a long aspect ratio were formed on the coating surface instead of the porous surface. The results revealed that the formed nanorods on the Ti surface were H2Ti5O11·H2O with the growth direction of [010]. This as-prepared Ti plate with a nanorod array surface exhibits a super-hydrophilic property, an excellent apatite-inducing ability and photocatalytic properties due to the existence of OH groups in the atomic structure of H2Ti5O11·H2O. The incorporated elements of Ca, P, Si and Na, and the corrosive attack of OH groups are the two factors for the formation of H2Ti5O11·H2O. The long and thin nature of the nanorods is attributed to the anisotropy of the atomic structure of H2Ti5O11·H2O with the lowest strain energy along the [010] direction based on the solid phase transformation.

J0330201 化学反応を利用した無機多孔体の合成プロセスと用途展開

Porous metals, which contain large amount of pores inside, exhibit various unique physical and mechanical properties, such as low bulk density and high strain energy absorbing capability. In this presentation, a novel processing method (reactive precursor method) to synthesize high-melting point porous metals and an attempt to control the cell structure are discussed. A precursor is made by blending two or more kinds of elemental powders. The precursor is then heated to ignite an exothermic reaction between the elemental powders. The closed-cell porous structure is obtained when the maximum temperature during the reaction exceeds the melting point of the reaction product, and open-cell porous structure is obtained when the maximum temperature is below the melting point. Therefore, if the optimum porous structure is the closed cell, then an additive powder (exothermic agent powder) which releases large amount of heat of reaction should be additionally blended. By blending additive powders in the precursor, the maximum temperature can be controlled. Aside from the additive powders, replication powders are also used to extend the diversity of cell morphology. Closed, flat, open, bimodal-sized and high-porosity open pores are currently achieved by the reactive precursor process.

Computational Simulations of Bone Remodeling under Natural Mechanical Loading or Muscle Malfunction Using Evolutionary Structural Optimization Method

Live bone inherently responds to applied mechanical stimulus by altering its internal tissue composition and ultimately biomechanical properties, structure and function. The final formation may structurally appear inferior by design but complete by function. To understand the loading response, this paper numerically investigated structural remodeling of mature sheep femur using evolutionary structural optimization method (ESO). Femur images from Computed Tomography scanner were used to determine the elastic modulus variation and subsequently construct finite element model of the femur with stiffest elasticity measured. Major muscle forces on dominant phases of healthy sheep gait were imposed on the femur under static mode. ESO was applied to progressively alter the remodeling of numerically simulated femur from its initial to final design by iteratively removing elements with low strain energy density (SED). The computations were repeated with two different mesh sizes to test the convergence. The elements within the medullary canal had low SEDs and therefore were removed during the optimization. The SEDs in the remaining elements varied with angle around the circumference of the shaft. Those elements with low SED were inefficient in supporting the load and thus fundamentally explained how bone remodels itself with less stiff inferior tissue to meet load demand. This was in line with the Wolff’s law of transformation of bone. Tissue growth and remodeling process was found to shape the sheep femur to a mechanically optimized structure and this was initiated by SED in macro-scale according to traditional principle of Wolff’s law.

Molecular dynamics simulation of Al grain mixing in Fe/Ni matrices and its influence on oxidation

AlxNiyFe(1−x−y) alloys are structural materials with potential application in high-temperature oxidizing environments. These materials are of specific interest as they have the ability to develop an oxidation resistant surface layer. To study diffusion and oxidation processes related to this surface layer formation, the mixing behavior of different sized Al grains in pure Ni and Fe matrices, with approximate grain/matrix atom ratio of 1:3, at temperatures above and below the structure melting point, was studied using ReaxFF-based molecular dynamics simulations. The simulations have been carried out at constant pressure, with temperatures being stepwise ramped over the range of 300-3000 K. For the Ni matrix, our results indicated lower chemical strain energy for Al in the mixed alloy and completion of mixing at a lower temperature for the Fe matrix. These results confirm that the Al-Ni alloy is energetically more stable than the Al-Fe alloy, which is in agreement with experiment. Further, larger Al grains appear to be favorable for mixing with Fe matrix, whereas for Ni matrix, smaller Al grains appear to be favorable. We suggest that this Al grain size effect on mixing matrices is due to the differences in formation energies between Ni/Al and Fe/Al alloys and differences in Ni-Ni and Fe-Fe bond distances. We also performed additional cooling simulations over the temperature range of 3000-300 K. The simulations revealed that for the considered cooling rate Fe alloy solidifies at a lower temperature than Ni alloy. Moreover, both alloys solidify to chemically disordered crystalline structures, of which the Ni structure is less ordered than the Fe structure. Preliminary oxidation simulations of slab structures with single grain indicate that the dynamics of matrix/grain mixing processes have a pronounced influence on the oxidation reactions. We find that Al and Ni atoms in their unmixed state are the most active reactants towards oxygen, while the Al/Ni alloy and pure Fe layers show substantially slower oxidation kinetics.

Biomechanical Evaluation of a Novel Porous-Structure Implant: Finite Element Study

The biomechanical performance of a novel engineered porous-structure implant (EPSI) with various porosities and a conventional solid-structure implant (CSSI) was investigated and compared. The three-dimensional finite element method was applied to titanium dental implant models placed in a block of bone that included both cortical and medullary bone. Five different pore sizes and porosities of the EPSI (58% porosity [PSI-58], 62% porosity [PSI-62], 71% porosity [PSI-71], 75% porosity [PSI-75], and 79% porosity [PSI-79]), were compared with the CSSI. Equivalent von Mises (EQV) stress, strain energy density, and displacement were examined for each implant design. The maximum EQV stresses exhibited in cortical bone of the EPSI models were lower than those of the CSSI model. Higher EPSI porosity tended to increase the EQV stress. The EPSI appeared to share the load with the cortical bone, as evidenced by lower strain energy density in the cortical bone of EPSI models. High values for displacement were observed at the coronal part of the implant in all models. Slight differences in maximum displacement values were seen between EPSI and CSSI models. The EPSI effectively reduced the maximum EQV stress in the cortical bone and enhanced the load-sharing capacity. A significant amount of energy was absorbed by the implant instead of being transferred to the surrounding cortical bone. Varying the porosity of an implant had less effect on implant displacement.

Mechanical and morphological properties of trabecular bone samples obtained from third metacarpal bones of cadavers of horses with a bone fragility syndrome and horses unaffected by that syndrome

To determine morphological and mechanical properties of trabecular bone of horses with a bone fragility syndrome (BFS; including silicate-associated osteoporosis). Cylindrical trabecular bone samples from the distal aspects of cadaveric third metacarpal bones of 39 horses (19 horses with a BFS [BFS bone samples] and 20 horses without a BFS [control bone samples]). Bone samples were imaged via micro-CT for determination of bone volume fraction; apparent and mean mineralized bone densities; and trabecular number, thickness, and separation. Bone samples were compressed to failure for determination of apparent elastic modulus and stresses, strains, and strain energy densities for yield, ultimate, and failure loads. Effects of BFS and age of horses on variables were determined. BFS bone samples had 25% lower bone volume fraction, 28% lower apparent density, 18% lower trabecular number and thickness, and 16% greater trabecular separation versus control bone samples. The BFS bone samples had 22% lower apparent modulus and 32% to 33% lower stresses, 10% to 18% lower strains, and 41 % to 52% lower strain energy densities at yield, ultimate, and failure loads, compared with control bone samples. Differences between groups of bone samples were not detected for mean mineral density and trabecular anisotropy. Results suggested that horses with a BFS had osteopenia and compromised trabecular bone function, consistent with bone deformation and pathological fractures that develop in affected horses. Effects of this BFS may be systemic, and bones other than those that are clinically affected had changes in morphological and mechanical properties.

BaTiO3-based nanolayers and nanotubes: First-principles calculations

The first-principles calculations using hybrid exchange-correlation functional and localized atomic basis set are performed for BaTiO(3) (BTO) nanolayers and nanotubes (NTs) with the structure optimization. Both the cubic and the ferroelectric BTO phases are used for the nanolayers and NTs modeling. It follows from the calculations that nanolayers of the different ferroelectric BTO phases have the practically identical surface energies and are more stable than nanolayers of the cubic phase. Thin nanosheets composed of three or more dense layers of (0 1 0) and (0 1 1[overline]) faces preserve the ferroelectric displacements inherent to the initial bulk phase. The structure and stability of BTO single-wall NTs depends on the original bulk crystal phase and a wall thickness. The majority of the considered NTs with the low formation and strain energies has the mirror plane perpendicular to the tube axis and therefore cannot exhibit ferroelectricity. The NTs folded from (0 1 1[overline]) layers may show antiferroelectric arrangement of Ti-O bonds. Comparison of stability of the BTO-based and SrTiO(3)-based NTs shows that the former are more stable than the latter.

Improved elastomeric seal design based on nonhomogeneous material properties

The goal of this research was improving elastomeric seal performance based on seal material design. The specific seal failure mode considered was permanent deformation or compression set of O-rings, and sealing performance degradation due to this process is common to all types of elastomeric seals. The basis for seal design was identified as reducing the elastic strain energy in the seal since it drives the growth of permanent material deformation. The design concept developed was using variation of material behavior over the seal section to manipulate the level and distribution of elastic strain energy. Design studies used finite element analyses with experimentally measured material behavior to quantify effects of varying seal material characteristic on seal performance. Sealing performance was described in terms of compression set and seal-counterface contact pressure. Experimental O-rings were produced based on designs that included regions of less stiff material in the larger surrounding seal section. Performance of new design seals was compared to conventional one-material seals and improved sealing performance was demonstrated. With the modified design seals, both compression set and the rate of sealing contact pressure loss over time were decreased. There was a loss of initial maximum contact pressure with the inclusion of less stiff material regions, but it was shown that this effect can be mitigated by properly locating the softer material in the overall seal section. In summary, properly implemented material variations over the seal will result in lower strain energy content, lower rate of permanent deformation development and decreasing rate of loss of seal-counterface contact pressure.

The cage strain energies of high-energy compounds

In this paper the cage strain energies of polynitroadamantanes, polynitrocubanes, hexanitrohexaazaisowurtzitane (HNIW or Cl-20), and some polynitrogen compounds were systematically calculated by density functional theory BOP/TNP method and the designs of homodesmotic reactions. The cage strain energies of polynitroadamantanes and polynitrocubanes increase gradually with the increase of the nitro-substituted number. However, the increase of the cage strain energies of polynitroadamantanes is less drastic than that of polynitrocubanes; on the contrary, the decrease of the bond dissociation energies of C–NO2 bonds in the former compounds is more rapidly than the latter. Accordingly, the cage strain energies and bond dissociation energies of C–NO2 bonds play different roles in determining the stability of high-energy compounds. An increase in the number of nitro groups may be advantageous to the performance and oxygen balance, but disadvantageous to the stability; an increase of cage strain energy may result in a decrease of stability, but more energy will release when a cage opening occurs. Rational number of nitro groups and proper cage strain energy are indispensable for an ideal nitro-containing explosive with high energy but insensitive to external impact. Polynitrogen compounds are high in cage strain energies, this may be why fewer polynitrogen compounds have been synthesized, so far. A proper design may harvest some polynitrogen compounds with low cage strain energies and high stability.

Periodontal biomechanics: finite element simulations of closing stroke and power stroke in equine cheek teeth

BackgroundIn equine dentistry periodontal diseases, especially periapical inflammation, are frequently occurring problems. Anachoresis is believed to be the most common cause for the development of such disorders. Nevertheless, there is still no substantiated explanation why settlement of pathogen microorganisms occurs in equine periodontal tissues. It is expected that excessive strains and stresses occurring in the periodontal ligament (PDL) during the horse’s chewing cycle might be a predisposing factor. In this study this assumption was examined by finite element (FE) analyses on virtual 3-D models of equine maxillary and mandibular cheek teeth, established on the basis of μCT datasets. Calculations were conducted both under conditions of closing and power stroke.ResultsResults showed a uniform distribution of low stresses and strain energy density (SED) during closing stroke, whereas during power stroke an occurrence of high stresses and SED could be observed in the PDL near the alveolar crest and in periapical regions.ConclusionThe concentration of forces during power stroke in these specific areas of the PDL may cause local tissue necrosis and inflammation and thus establish a suitable environment for the settlement of microorganisms.