Abstract Cellular solids are instrumental in creating lightweight, strong, and damage-tolerant engineering materials. By extending feature size down to the nanoscale, we simultaneously exploit architecture material effects substantially enhance structural integrity of architected meta-materials. We discovered that hollow-tube alumina nanolattices with 3D kagome geometry contained pre-fabricated flaws always failed at same load as pristine specimens when ratio notch length (a) sample width...

We simulate and analyze the instability of wrinkles creases in highly deformable soft materials using a robust method point perturbation free surfaces. This enables us to identify distinct regimes wrinkle crease such as elastomers hydrogels, ascertain critical conditions for onset these two modes instability. Furthermore, we show wide range that encompasses Biot's linear stability analysis on surface beyond. approach provides practical route experimentalists their investigations...

Abstract The microstructure formation during <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>β</mml:mi> <mml:mo>→</mml:mo> <mml:mi>α</mml:mi> <mml:mo>+</mml:mo> </mml:math> transformation in heat affected zone of titanium alloy welds is studied using an approach combining a phase field solid-solid model with transfer finite element method (FEM). FEM used to macroscopic welding cycle and compute the thermal history at several points across weld....

Controlling the morphologies and properties of surface and/or interface bimaterials consisting soft polymers provides new opportunities in many engineering applications. Crease is a widely observed deformation mode nature applications for where smooth folds into region self-contact with sharp tip, usually induced by instability from mechanical compression or swelling. In this work, we explore competition mechanisms between creases through numerical simulations experimental studies on bilayer...

A great deal of effort has been made on the design and fabrication materials or structures that simultaneously possess ultra-high stiffness, strength, yet ultra-low density. Here, using finite element simulations, we hybrid comprising a space-filling nanolattice stretching-dominated plates study how failure strength mode such depend geometrical parameters nanolattice. It is found these can be tuned by changing parameters. In particular, show nearly linear scaling achieved between...

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This paper describes a finite element computational model for the study of initiation interface decohesion and subsequent delamination propagation in plastic IC packages. The effects thermal loading vapor-induced pressure on package failure are investigated using an traction-separation law. law, characterized by adhesion energy strength, is augmented micro-mechanics describing softening that caused vapor pressure-driven void growth. Parametric studies packages were carried out to understand...

Void growth and interaction in a soft material is explored numerically this work three-dimensional context. Discrete initially spherical voids are explicitly modeled ahead of crack front under small-scale yielding. While multiple void mechanism can be identified our study, computations show qualitatively similar exhibited for the initial volume fractions considered, f 0 = 0.1% 1%. Extensive damage process zone observed upon application load, with resultant deformed taking on prolated shape....

Nickel titanium (TiNi) shape memory alloy thin film is a promising candidate for microactuation because of its large deformation and recovery force, good electrical mechanical properties, long fatigue life, high corrosion resistance.

Abstract The strength and fracture toughness of polymer/silicon interfaces are sensitive to the porosity moisture content interface as well yield strain polymer. Moisture degrades interfaces. Rapidly expanding water vapor introduces high internal pressure within cavities thereby accelerating delamination by void growth coalescence. latter can cause a ten-fold decrease in interface. Vapor acting on delaminated surfaces contributes mode I component crack driving force. This increases...

An operational definition for the onset of void coalescence in incipient spall fracture ofductile solids is proposed. The deemed to occur when third invariant thetensorial form Hill–Mandel condition attains a zero value. allowsfor systematic investigations on effects dimensionless stress rate k and state,defined by triaxiality T Lode parameter L, coalescencevia micromechanical analyses. analyses reveal that critical macroscopic effectivestrain displays an increasing–decreasing transition...

IC packages exposed to humid environment are susceptible thin film adhesive failures during reflow soldering. Under temperatures, moisture trapped in the micropores of polymeric adhesives vaporizes and induces vapor pressure within these voids, accelerating failure via void growth. In this work, a computational discrete approach is adopted study rate-dependent growth layer under influence pressure. The model problem consists ductile with centerline crack, sandwiched between two elastic...

Abstract In this paper, we proposed a multi-tool modeling method to reduce the finite element simulation computational time of incremental sheet forming (ISF) process. The aim is study computation efficiency and prediction accuracy thickness reduction spring-back ISF part using model. tool paths necessary for were generated by an in-house code can be extended more complex geometries parts. allows tremendous reductions in CPU time. To verify method, models truncated cones shape compared...