Curvature Stress Research Articles

Stress evolution in AlN layers grown on c-Al2O3 by plasma-assisted molecular beam epitaxy at metal-rich conditions

Stress generation and relaxation in AlN nucleation and buffer layers grown on c-Al2O3 substrates by plasma-assisted molecular beam epitaxy at low (LT, TS = 780°C) and high (HT, TS = 850°C) substrate temperatures were studied. Oscillation behavior of the wafer curvature (stress×thickness) was revealed during pulsed deposition of AlN in metal modulated epitaxy and migration enhanced epitaxy modes under the metal-rich conditions, which corresponded to Al bilayer formation and consumption. Minimal average stress ∼ +0.05 GPa in AlN buffer layers was observed at LT growth, which increased up to +0.85 GPa at HT growth. In addition, the LT AlN layers demonstrated lower densities of screw and edge threading dislocations equal to 7.8·108, 5.1·109 cm−2, respectively, while in the case of HT AlN layers those densities were significantly higher.

Interaction of Artepillin C with model membranes: Effects of pH and ionic strength

Artepillin C is the major constituent of green propolis, one of the most consumed products in popular medicine owing to its therapeutic effects, including antitumor activity. Artepillin C differs from other cinnamic acid derivatives due to the presence of two prenylated groups in its structure, believed to enhance access to the cell membrane and resulting in pharmacological activity. The membrane outer leaflet of tumor cells is exposed to an acidic extracellular environment, which could modulate the protonation state of antitumor drugs and hence their interaction with the cell membrane. Herein, we investigated the interaction of Artepillin C with Langmuir monolayers and giant unilamellar vesicles (GUVs) of 1,2‑dipalmitoyl‑sn‑glycerol‑3‑phosphocholine (DPPC) used as model membranes, in physiological and acidic environments. We observed that protonation of the carboxyl group of Artepillin C is essential for the interaction, with larger shifts induced in the surface pressure isotherms of DPPC monolayers in comparison with deprotonated Artepillin C. Also observed was a decrease in lipid packing inferred from the compressibility modulus and Brewster angle microscopy (BAM) images for monolayers on acidic subphases. Results with microscopy techniques on GUVs confirmed that.Artepillin C causes a curvature stress of the lipid bilayer only in its neutral state, causing the GUVs to burst. The stronger effects of neutral Artepillin C on both monolayers and GUVs were maintained when the ionic strength was increased. Taken together, the results indicate that Artepillin C may have preferential attachment to a more acidic environment which might be an important feature for its antitumor activity.

Investigation of blank bow defect after roller leveller by finite element analysis

Sheet metal often shows curvature, shape defects and internal (residual) stresses which are not complying with the increasing requirements for the quality needed for customers. Roller levelling is one of the ways to flatten a metal sheets. The setting up of such machines is extremely complex and mainly depends on the operator’s experience. The main objective of this paper is investigation of adjustable parameters of roller leveller together with elastic-plastic material behaviour on the internal stresses formation. High and unbalanced values of residual stresses lead to blank bow defects in a final product. In this study, numerical finite element (FE) 2D-model of roller levelling process is proposed to use. Properties of the material were determined experimentally. The blank bow magnitude was simulated and compared with experimental results and have a good accuracy for FE prediction.

Semi-analytical solutions of ultimate load for a rectangular concrete-filled tubular column subjected to eccentric compression

This paper presents a semi-analytical method (SAM) to predict accurately the ultimate capacity of a rectangular concrete-filled tubular (RCFT) column subjected to eccentric compression. In this method, the analytical equations are established based on all the possible stress states of the section. Specifically, each equation set contains the equilibrium equations, extremum equations, curvature–deflection equation and stress–curvature equation. The predicted ultimate load is solved by numerical solution of equation sets. The proposed approach chose an accurate piecewise-nonlinear constitutive model for confined concrete considering beneficial confinement effect of rectangular steel tube. The pre-existing relevant tests and finite element method (FEM) were compared with the proposed SAM to verify the accuracy and applicability of predicted ultimate loads by SAM, and parameters analyses for aspect ratio, steel strength, depth-to-thickness ratio and length-to-depth ratios were studied by proposed SAM to determine these effects on N–M interaction curve of RCFT columns. The comparison indicates that the proposed SAM is accurate in predicting the ultimate loads of RCFT columns under eccentric compression.

Stress Relaxation Mechanism after Thinning Process on 4H-SiC Substrate

In this work a comparison between different 6 inches 4H-SiC commercial substrates after post processing has been shown. The main comparison was done between two different suppliers after a thinning process that leaves the sample with a final thickness of 150 microns. After the processing the two substrates show different behavior with different curvature and residual stress. X-Ray diffraction show different crystal quality and curvature values of the substrates. Micro-Raman show different residual stress of the substrates before and after the thinning process. Moreover, molten KOH etching for dislocation detection also show different value of dislocation density for both substrates.

Analysis of substrate curvature and film stress through a reformed mathematical description on mismatch strain

Stoney’s formula first related film stress to substrate curvature, but properties of film material were not contained in it, which was modified by Freund’s formula. In the derivation of Freund’s formula, a uniformly preassigned mismatch strain throughout film was adopted. For the epitaxial growth of film on substrate, the present paper suggests a different imagination that the deformation of the film-substrate system attributed to the mismatch between two crystals is produced in the following way: a coupled lattice constant emerged at the interface is shared by film and substrate, by which the interaction between film and substrate, and then the development of stress and strain fields in the bilayer structure are induced naturally. As a result, a theoretical model with a closed form for calculating the substrate curvature and the corresponding film stress has been established, the validity of which has been confirmed by compared with Stoney’s formula and Freund’s formula via examples. Our analysis is limited to the linear small deformation, but the new understanding on the mismatch strain can be extended to the nonlinear analysis on the large deformation.

HaloTag Assay Suggests Common Mechanism of E. coli Membrane Permeabilization Induced by Cationic Peptides.

Permeabilization of the Gram-negative bacterial outer membrane (OM) by antimicrobial peptides (AMPs) is the initial step enabling access of the AMP to the cytoplasmic membrane. We present a new single-cell, time-resolved fluorescence microscopy assay that reports on the permeabilization of the E. coli OM to small molecules with a time resolution of 3 s or better. When profluorophore JF646 (702 Da) crosses the outer membrane (OM) and gains access to the periplasm, it binds to the localized HaloTag protein (34 kDa) and fluoresces in a characteristic hollow spatial pattern. Previous work used the much larger periplasmic GFP (27 kDa) probe, which reports on OM permeabilization to globular proteins. We test the assay on three cationic agents: Gellman random β-peptide copolymer MM63:CHx37, human AMP LL-37, and synthetic hybrid AMP CM15. These results combined with the previous work suggest a unifying sequence of OM and cytoplasmic membrane (CM) events that may prove commonplace in the attack of cationic peptides on Gram-negative bacteria. The peptide initially induces gradual OM permeabilization to small molecules, likely including the peptide itself. After a lag time, abrupt permeabilization of the OM, abrupt resealing of the OM, and abrupt permeabilization of the CM (all to globular proteins) occur in rapid sequence. We propose a mechanism based on membrane curvature stress induced by the time-dependent differential binding of peptide to the outer leaflet of the OM and CM. The results provide fresh insight into the critical OM-permeabilization step leading to a variety of damaging downstream events.

Atypical Binding Behavior of Epsin‐like Clathrin Adaptor 1 to Diacylglycerol Pyrophosphate

Epsin N‐terminal homology (ENTH) and AP‐180 N‐terminal homology (ANTH) domain proteins are membrane binding proteins known to interact with polyphosphoinositides (PIPs). They share function, structure and sequence similarity, and are grouped together as A/ENTH domain proteins. The ENTH domain contains a distinctive N‐terminal helix (Ho) region that plays a crucial role in membrane bending. This Ho helix is not usually found in ANTH domains. Epsin‐like Clathrin Adaptor 1 (ECA1) is one such A/ENTH protein that acts as an adaptor protein in clathrin mediated endocytosis. It interacts with clathrin via its C‐terminus, and PIPs via its N‐terminus. In addition to having ANTH domain sequence similarity, ECA1 also contains the distinctive Ho helix region that is generally found in the ENTH domain. ECA1 is therefore best characterized as an N‐ANTH domain protein with a unique combination of both ANTH and ENTH regions. ECA1 is known to play a role in stress signaling in plants and also binds to phosphatidic acid (PA) upon salt stress. Like proteins, membrane lipids undergo drastic changes during stress stimuli. PA is a lipid second messenger that rapidly and transiently increases under stress stimuli. Upon rise of PA levels another lipid, diacylglycerol pyrophosphate (DGPP) starts to accumulate. DGPP is phosphorylated PA. It is suggested to be synthesized at higher levels as a signal for PA attenuation during stress. We recently showed in vitro that ECA1‐PA ‐affinity is modulated as a function of membrane curvature stress. In this research, we investigate ECA1 affinity to DGPP. We hypothesize that the PA target ECA1 has affinity for its metabolite DGPP which is highly negatively charged and this affinity is variable at varying pH. We tested ECA1 affinity to DGPP using liposome binding assay along with other anionic lipids; i.e., phosphatidylserine, phosphatidylinositol (4)‐phosphate and phosphatidylinositol (4,5)‐bisphosphate in the presence and absence of phosphatidylethanolamine. Our results show striking evidence that protein‐lipid interactions are not simply based on electrostatics. We also show that higher charge density on membranes does not always correspond to higher protein affinity. In fact, DGPP showed lesser protein binding to ECA1 compared to PA although DGPP has a higher negative charge. This study brings us a step closer towards understanding the complexity of protein interactions with anionic lipids and opens the discussion to lipid homeostasis upon salt stress.Support or Funding InformationDepartment of Biological Science, Kent State University and NSF CHE 1412920This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Ion Channels Induced by Antimicrobial Agents in Model Lipid Membranes are Modulated by Plant Polyphenols Through Surrounding Lipid Media.

The potential therapeutic applications of plant polyphenols in various neurological, cardiovascular, metabolic and malignant disorders determine the relevance of studying the molecular mechanisms of their action on the cell membranes. Here, the quantitative changes in the physical parameters of model bilayer lipid membranes upon the adsorption of plant polyphenols were evaluated. It was shown that butein and naringenin significantly decreased the intrinsic dipole potential of cholesterol-free and cholesterol-enriched membranes. Cardamonin, 4'-hydroxychalcone, licochalcone A and liquiritigenin demonstrated the average efficiency, while resveratrol did not characterized by the ability to modulate the bilayer electrostatics. At the same time, the tested polyphenols affected melting of phospholipids with saturated acyl chains. The effects were attributed to the lipid disordering and a promotion of the positive curvature stress. According to DSC data and results of measurements of the threshold voltages that cause bilayer breakdown licochalcone A is the most effective agent. Furthermore, the role of the polyphenol induced changes in the electric and elastic properties of lipid host in the regulation of reconstituted ion channels was examined. The ability of the tested polyphenols to decrease the conductance of single ion channels produced by the antifungal cyclic lipopeptide syringomycin E was in agreement with their effects on the dipole potential of the lipid bilayers. The greatest effect of licochalcone A on the steady-state membrane conductance induced by the antifungal polyene macrolide antibiotic nystatin correlated with its greatest efficacy to induce the positive curvature stress. We also found that butein and naringenin bind specifically to a single pore formed by α-hemolysin from Staphylococcus aureus.

Lipid-mediated mode of action of local anesthetics on lipid pores induced by polyenes, peptides and lipopeptides.

The effects of local anesthetics (LAs), namely, lidocaine (LDC), prilocaine (PLC), mepivacaine (MPV), bupivacaine (BPV), procaine (PC), and tetracaine (TTC), on the steady-state transmembrane conductance induced by the cis-side addition of the antifungal polyene macrolide antibiotic, nystatin (NYS), in planar lipid bilayers were studied. The addition of TTC to model membranes comprising DOPC and cholesterol (33 mol%) led to a nearly twenty-fold increase in the steady-state NYS-induced membrane conductance. BPV slightly enhanced the channel-forming activity of polyene. LDC, PLC, MPV, and PC did not affect the NYS-induced transmembrane current. We concluded that the effects of LAs on the channel-forming activity of NYS were in agreement with their effects on the elastic properties of model membranes. The ability of aminoamide LAs to promote calcein leakage from large unilamellar DOPC-vesicles was decreased in the following order: BPV >> LDC ≈ PLC ≈ MPV. LDC, PLC, and MPV produced a graded leakage of fluorescent marker from liposomes, up to 10-13%. A initial sharp jump in fluorescence after the introduction of BPV was attributed to the solubilization of liposomes and the formation of mixed DOPC:BPV-micelles. Differential scanning microcalorimetry (DSC) of large unilamellar DPPC-vesicles showed that the main transition temperature (Tm) is continuously decreased upon increasing concentrations of TTC. A sharp drop in the enthalpy of the transition at higher TTC concentrations indicated a formation of anesthetic/lipid mixed micelles. In contrast to TTC, PC slightly decreased Tm, broadened the DSC signal and did not provoke vesicle-to-micelle transition. Both the calcein leakage and DSC data together with the results of measurements of threshold voltages that are required to cause the lipid bilayer breakdown might indicate an alteration in the curvature lipid packing stress, induced by BPV and TTC. The data presented here lend support to a lipid-mediated mode of LAs action on NYS pores via an alteration in curvature stress near the trans-mouth. Similar results were obtained for several lipid pores, formed by polyene amphotericin B, lipopeptide syringomycin E, and the peptides magainin and melittin. This finding further developed the concept of non-specific regulation of lipid pores by LAs. In conclusion, the combination of nystatin with LAs could be a novel treatment for efficient therapy of superficial and mucosal candidiasis.

Electrostatic stiffening and induced persistence length for coassembled molecular bottlebrushes.

A self-consistent field analysis for tunable contributions to the persistence length of isolated semiflexible polymer chains including electrostatically driven coassembled deoxyribonucleic acid (DNA) bottlebrushes is presented. When a chain is charged, i.e., for polyelectrolytes, there is, in addition to an intrinsic rigidity, an electrostatic stiffening effect, because the electric double layer resists bending. For molecular bottlebrushes, there is an induced contribution due to the grafts. We explore cases beyond the classical phantom main-chain approximation and elaborate molecularly more realistic models where the backbone has a finite volume, which is necessary for treating coassembled bottlebrushes. We find that the way in which the linear charge density or the grafting density is regulated is important. Typically, the stiffening effect is reduced when there is freedom for these quantities to adapt to the curvature stresses. Electrostatically driven coassembled bottlebrushes, however, are relatively stiff because the chains have a low tendency to escape from the compressed regions and the electrostatic binding force is largest in the convex part. For coassembled bottlebrushes, the induced persistence length is a nonmonotonic function of the polymer concentration: For low polymer concentrations, the stiffening grows quadratically with coverage; for semidilute polymer concentrations, the brush chains retract and regain their Gaussian size. When doing so, they lose their induced persistence length contribution. Our results correlate well with observed physical characteristics of electrostatically driven coassembled DNA-bioengineered protein-polymer bottlebrushes.

New type of γ′ phase in Ni based single crystal superalloys: Its formation mechanism and strengthening effect

New type of γ′-precipitate in Ni-(6-8)Al-(7-12)Mo-4.5Ta-1.5Re (weight%) single-crystal superalloys and its effect on mechanical properties have been investigated. The phase exhibits a rattan form from cross-sectional observation while a curved thin film in stereoscopic structure. Its density is strongly linked to Al and Mo contents and holding time of solid solution. Its formation arises as a result of i) the overlap of γ′-precipitate and ii) the subsequent interface migration; the former is caused by the mismatch of γ-γ′ periodicity, which is inherited from the congruent ordering and spinodal decomposition independently occurring in different regions; the latter is driven from the chemical potential difference between γ-ribbon and γ′-precipitate induced by interface curvature and misfit stress. The γ′-rattan improves room temperature tensile properties through changing the slip lines and inhibiting the crack growth, which is ascribed to the change in the stress field of γ-γ′ structure.

Melittin-Induced Permeabilization, Re-sealing, and Re-permeabilization of E. coli Membranes

The permeabilization of model lipid bilayers by cationic peptides has been studied extensively over decades, with the bee-sting toxin melittin perhaps serving as the canonical example. However, the relevance of these studies to the permeabilization of real bacterial membranes by antimicrobial peptides remains uncertain. Here, we employ single-cell fluorescence microscopy in a detailed study of the interactions of melittin with the outer membrane (OM) and the cytoplasmic membrane (CM) of live Escherichia coli. Using periplasmic green fluorescent protein (GFP) as a probe, we find that melittin at twice the minimum inhibitory concentration first induces abrupt cell shrinkage and permeabilization of the OM to GFP. Within ∼4 s of OM permeabilization, the CM invaginates to form inward facing “periplasmic bubbles.” Seconds later the bubbles begin to leak periplasmic GFP into the cytoplasm. Permeabilization is localized, consistent with possible formation of toroidal pores. Within ∼20 s, first the OM and then the CM re-seals to GFP. Some 2–20 min later, both CM and OM are re-permeabilized to GFP. We invoke a mechanism based on curvature stress concepts derived from model bilayer studies. The permeabilization and re-sealing events involve sequential, time-dependent build-up of melittin density within the outer and inner leaflets of each bilayer. We also propose a mechanical explanation for the early cell shrinkage event induced by melittin and a variety of other cationic peptides. As peptides gain access to the periplasm, they bind to the anionic peptido-crosslinks of the lipopolysaccharide layer, increasing its longitudinal elastic modulus. The cell wall shrinks because it can withstand the same turgor pressure with smaller overall extension. Shrinkage in turn induces invagination of the CM, preserving its surface area. We conclude by comparing the behavior of different peptides.

Lipid-mediated regulation of pore-forming activity of syringomycin E by thyroid hormones and xanthene dyes

The effects of dipole modifiers, thyroid hormones (thyroxine and triiodothyronine) and xanthene dyes (Rose Bengal, phloxineB, erythrosin, eosinY and fluorescein) on the pore-forming activity of the lipopeptide syringomycin E (SRE) produced by Pseudomonas syringae were studied in a model bilayer. Thyroxine does not noticeably influence the steady-state number of open SRE channels (Nop), whereas triiodothyronine decreases it 10-fold at −50mV. Rose Bengal, phloxine B and erythrosin significantly increase Nop by 350, 100 and 70 times, respectively. Eosin Y and fluorescein do not practically affect the pore-forming activity of SRE. Recently, we showed that hormones decrease the dipole potential of lipid bilayers by approximately 60mV at 50μM, while Rose Bengal, phloxine B and erythrosin at 2.5μM reduce the membrane dipole potential by 120, 80 and 50mV, respectively. In the present study using differential scanning microcalorimetry, confocal fluorescence microscopy, the calcein release technique and measurements of membrane curvature elasticity, we show that triiodothyronine strongly affects the fluidity of model membranes: its addition leads to a significant decrease in the temperature and cooperativity of the main phase transition of DPPC, calcein leakage from DOPC vesicles, fluidization of solid domains in DOPC/DPPC liposomes, and promotion of lipid curvature stress. Thyroxine exerts a weaker effect. Xanthene dyes do not influence the phase transition of DPPC. Despite the decrease in the dipole potential, thyroid hormones modulate SRE channels predominantly via the elastic properties of the membrane, whereas the xanthene dyes Rose Bengal, phloxine B and erythrosine affect SRE channels via bilayer electrostatics.

Effect of nozzle size scaling in co-flow water cavitation jet peening

Water Cavitation Peening (WCP) employs cavitation to introduce compressive residual stresses in metals while limiting the surface roughening typical of similar surface enhancement processes such as shot peening and laser shock peening. As shown by a number of authors, cavitation intensity is greatly affected by the jet velocity as well as by the nozzle dimensions and shape. This paper reports on an investigation how nozzle dimensions affect cavitation intensity and peening performance in co-flow WCP of Al 7075-T651. Scalability of the process is investigated by comparing co-flow nozzles of increasing size but the same diameter ratios. The results show a substantial increase in cavitation intensity with nozzle size and a considerable decrease in the processing time required for saturation of the strip curvature and residual stress. The observed trends are explained by means of high-speed video imaging analysis and pitting tests, which show that the increase in cavitation intensity is due to an increase in the amount of cavitation when nozzle dimensions increase, while the pit depths and pit shape factor, which are measures of the strength of the cavitation events occurring at the workpiece surface, are largely unaffected. The process yields compressive residual stresses as high as 400MPa and as deep as 350μm below the surface, which are both a significant improvement upon previous results reported for shot peening.

Numerical investigation of the combined effects of curvature and normal stress on sheet metal formability

A number of parts and components involved in the automotive industry are made of thin bent sheets, which are subjected to out-of-plane compressive stresses in addition to traditional in-plane stresses. Unfortunately, the classical predictions based on the conventional concept of Forming Limit Diagram (FLD) are no longer relevant when the strain distribution is heterogonous over the sheet thickness. Therefore, this conventional FLD concept is not capable of accounting for the effect of out-of-plane stresses on the onset of localized necking. The aim of the present contribution is to propose an extension of the well-known Marciniak–Kuczynski approach to simultaneously account for the effect of curvature and normal stress on formability prediction. The new developed tool allows predicting the limit strains for the whole range of strain paths. The mechanical behavior of the studied sheets follows the rigid–plastic flow theory. Through numerical results, it is shown that both curvature and normal stress tend to increase the formability limit of the sheet metal.

The role of nonbilayer phospholipids in mitochondrial structure and function.

Mitochondrial structure and function are influenced by the unique phospholipid composition of its membranes. While mitochondria contain all the major classes of phospholipids, recent studies have highlighted specific roles of the nonbilayer-forming phospholipids phosphatidylethanolamine (PE) and cardiolipin (CL) in the assembly and activity of mitochondrial respiratory chain (MRC) complexes. The nonbilayer phospholipids are cone-shaped molecules that introduce curvature stress in the bilayer membrane and have been shown to impact mitochondrial fusion and fission. In addition to their overlapping roles in these mitochondrial processes, each nonbilayer phospholipid also plays a unique role in mitochondrial function; for example, CL is specifically required for MRC supercomplex formation. Recent discoveries of mitochondrial PE- and CL-trafficking proteins and prior knowledge of their biosynthetic pathways have provided targets for precisely manipulating nonbilayer phospholipid levels in the mitochondrial membranes in vivo. Thus, the genetic mutants of these pathways could be valuable tools in illuminating molecular functions and biophysical properties of nonbilayer phospholipids in driving mitochondrial bioenergetics and dynamics.

Probability analysis of double layer barrel vaults considering the effect of initial curvature and length imperfections simultaneously

Load carrying capacity of reticulated space structures majorly depend on the structures’ imperfections. Imperfections in initial curvature, length, and residual stress of members are all innately random and can affect the load-bearing capacity of the members and consequently that of the structure. The present study investigated the effect of the probability distribution of initial curvature imperfection and lack of fit of members on the load-bearing capacity of double-layer barrel vault space structures with different types of support. A random number was first assigned to each member using gamma and normal distributions for initial curvature and member length imperfections, respectively. Afterwards, the ultimate bearing capacity and the collapse behavior of the structure was determined using nonlinear finite-element analysis in OpenSees software and finally structures reliability was acquired. The results demonstrate that the collapse behavior of doable-layer barrel vault space structures is sensitive to the random distribution of initial imperfections.

Mechanistic modeling of the liquid film shape and heat transfer coefficient in annular-regime microchannel flow boiling

A methodology is proposed for predictive modeling of the liquid-gas interface shape and saturated flow boiling heat transfer coefficient in two-phase microchannel flows within the annular regime. The mechanistic model accounts for the effects of surface tension and interface curvature, gravity, and shear stress in determining the liquid film shape; one-dimensional conduction is assumed to occur across the variable-thickness film to calculate wall heat transfer coefficients locally along the channel length. Model performance is benchmarked against 251 experimentally measured heat transfer coefficient values taken from the literature for annular-regime flow boiling in microchannels of a rectangular cross-section. These data are successfully predicted with a mean absolute error of 21.7%, and 72.1% of the points lie within an error band of ±30%. The match to data is poorest at lower vapor qualities corresponding to the onset of the annular regime, for which the heat transfer coefficient is underpredicted; an experimental investigation is performed to better understand the disparity under these operating conditions. Liquid film shapes are measured during adiabatic annular flow through microchannels of square cross-section for a range of channel hydraulic diameters (160µm, 510µm, 1020µm) and operating conditions, so as to control the void fraction and Weber number of the flow. Using air and water as the working gas and liquid, respectively, trends in film behavior are identified and compared against model predictions. The experimental findings reveal the non-negligible impact of capillary pumping on the interface morphology at the onset of the annular regime.

The Relationship Between Surface Curvature and Abdominal Aortic Aneurysm Wall Stress.

The maximum diameter (MD) criterion is the most important factor when predicting risk of rupture of abdominal aortic aneurysms (AAAs). An elevated wall stress has also been linked to a high risk of aneurysm rupture, yet is an uncommon clinical practice to compute AAA wall stress. The purpose of this study is to assess whether other characteristics of the AAA geometry are statistically correlated with wall stress. Using in-house segmentation and meshing algorithms, 30 patient-specific AAA models were generated for finite element analysis (FEA). These models were subsequently used to estimate wall stress and maximum diameter and to evaluate the spatial distributions of wall thickness, cross-sectional diameter, mean curvature, and Gaussian curvature. Data analysis consisted of statistical correlations of the aforementioned geometry metrics with wall stress for the 30 AAA inner and outer wall surfaces. In addition, a linear regression analysis was performed with all the AAA wall surfaces to quantify the relationship of the geometric indices with wall stress. These analyses indicated that while all the geometry metrics have statistically significant correlations with wall stress, the local mean curvature (LMC) exhibits the highest average Pearson's correlation coefficient for both inner and outer wall surfaces. The linear regression analysis revealed coefficients of determination for the outer and inner wall surfaces of 0.712 and 0.516, respectively, with LMC having the largest effect on the linear regression equation with wall stress. This work underscores the importance of evaluating AAA mean wall curvature as a potential surrogate for wall stress.