Now showing items 9-28 of 47

    • A case for Tsai's Modulus, an invariant-based approach to stiffness 

      Ateiro, Albertino; Sharma, Naresh; Melo, Jose Daniel Diniz; Seneviratne, Waruna P. (Elsevier, 2020-11-15)
      For the past six years, we have been benefiting from the discovery by Tsai and Melo (2014) that the trace of the plane stress stiffness matrix (tr(Q)) of an orthotropic composite is a fundamental and powerful scaling ...
    • Chapter 39 -- Updating composite materials handbook-17 volume 5— ceramic matrix composites 

      Douglas Kiser, J.; David, Kaia E.; Davies, Curtis; Missri-Andrulonis, Rachael; Ashforth, Cindy (Wiley, 2018)
      This chapter discusses the updated version of CMH‐17 Volume 5—Ceramic Matrix Composites handbook released in 2002, which provides a more comprehensive overview of current Ceramic Matrix Composites (CMC) technology. Emphasis ...
    • A combined X-Ray CT and mechanistic characterization of bearing failure mechanisms in bolted composite components 

      Cui, Xiaodong; Xiao, Jian; Lua, Jim Y.; Kariyawasam, Supun; Fulghum, Ethan; Saathoff, Caleb (Vertical Flight Society, 2021-05)
      This paper presents the characterization of bearing failure mechanisms in composite joints with countersunk bolt by applying an X-ray Computed Tomography (XCT) technique and a developed bearing failure model to build the ...
    • Composite drilling characterization and performance evaluation 

      Xiao, Jian; Pham, Dinh Chi; Lua, Jim Y.; Saathoff, Caleb; Seneviratne, Waruna P. (DEStech Publications, 2019-09)
      Hole drilling is one of the most widely used operations in order to place bolts or rivets. Drilling holes in composites leads to drilling-induced defects and damages such as delamination, burr, microcracking, swelling, ...
    • Compressive response of composite laminates with defects 

      Cui, Xiaodong; Karuppiah, Anand Vijay; Pham, Dinh Chi; Lua, Jim Y.; Saathoff, Caleb; Seneviratne, Waruna P. (American Institute of Aeronautics and Astronautics Inc, 2020-01-05)
      Defects are inevitable in the manufacture and service of composite laminates and their influence on the mechanical performance of composite laminates can be substantial. Ply waviness and delamination are two major types ...
    • Coupon-level mechanical testing for polymer-based additive manufacturing 

      Park, Chul Y.; Rupel, Keith E.; Henry, Chelsey E.; Palliyaguru, Upul R. (ASTM International, 2020-06-04)
      The term additive manufacturing (AM) is used to describe processes of joining materials to make parts from a three-dimensional model data, as opposed to subtractive manufacturing. Although AM technology offers potential ...
    • Crack length correction and root rotation angle in a sandwich single cantilever beam (SCB) fracture specimen 

      Saseendran, Vishnu; Carlsson, Leif A.; Berggreen, Christian; Seneviratne, Waruna P. (KeAi Publishing Communications Ltd, 2020-12)
      Crack root rotation is a measure of deviation from clamped boundary conditions of region in front of the crack tip. The root rotation depends on the shear force and bending moment acting at the crack tip. Such rotation ...
    • Crashworthiness by analysis: verifying FEA modeling capabilities by accident reconstruction 

      Zinzuwadia, Chandresh M.; Olivares, Gerardo; Ly, Hoa T.; Gomez Valbuena, Luis M. (ASCE, 2018-11-15)
      A finite element (FE) model of a generic single-aisle narrow body transport aircraft was used for computational crash analysis to compare simulated deformations to those observed in the Turkish Airline Flight 1951 crash ...
    • Damage growth analysis of sandwich structures subjected to combined compression and pressure loading 

      Seneviratne, Waruna P.; Tomblin, John S.; Perera, Shenal; Varatharaj, Pirashandan (DEStech Publications, 2019-09)
      Fluid-ingression phenomena in composite sandwich structures is a concern for components employed in the aerospace industry. Poor design/material selections, impact damages, thermo-mechanical loads occurring during ...
    • Damage initiation and fracture analysis of honeycomb core single cantilever beam sandwich specimens 

      Saseendran, Vishnu; Varatharaj, Pirashandan; Perera, Shenal; Seneviratne, Waruna P. (SAGE, 2020-04-27)
      Fracture testing and analysis of aerospace grade honeycomb core sandwich constructions using a single cantilever beam test methodology is presented here. Influence of various parameters such as facesheet thickness, core ...
    • Damage mechanisms in tapered composite structures under static and fatigue loading 

      Rao, Prabhakar M.; Gurvich, Mark R.; Palliyaguru, Upul R.; Seneviratne, Waruna P. (DEStech Publications, 2019-09)
      In this work an integrated computational/experimental approach was developed to validate the predictive capabilities of State-of-the-Art (SoA) Progressive Damage Analysis (PDA) methods and tools. Specifically, a tapered ...
    • Defects characterization and evaluation of their effects on compressive failure of composite components 

      Cui, Xiaodong; Pham, Dinh Chi; Karuppiah, Anand Vijay; Lua, Jim Y.; Saathoff, Caleb; Seneviratne, Waruna P. (DEStech Publications, 2019-09)
      In the design and certification of composite structural components for aircrafts, compression and combined compression and shear loading cases have to be considered. Various forms of defects such as ply waviness, delamination ...
    • Defects characterization, damage mapping, and property evaluation of composites 

      Lua, Jim Y.; Sadeghirad, Alireza; Cui, Xiaodong; Karuppiah, Anand Vijay; Saathoff, Caleb; Seneviratne, Waruna P. (DEStech Publications Inc., 2018)
      The presence of voids in the composite laminates can reduce the mechanical properties in composites and these voids can become precursors in the activation of other failure modes such as delamination. Knowing the volume ...
    • Development and validation of finite element impact models of high-density UAS components for use in air-to-air collision simulations 

      Kota, Kalyan Raj; Ricks, Trent; Gomez Valbuena, Luis M.; Monteros, Jaime Espinosa De Los; Olivares, Gerardo; Lacy, Thomas E. (Taylor and Francis Inc., 2020-05-18)
      Understanding the severity of mid-air collisions between lightweight fixed-wing unmanned aerial systems (FW-UASs) and manned aircraft is a critical flight safety issue. Finite element models of high-density FW-UAS components ...
    • Effects of refill friction stir spot weld spacing and edge margin on mechanical properties of multi-spot-welded panels 

      Balasubramaniam, Guruvignesh Lakshmi; Boldsaikhan, Enkhsaikhan; Fukada, Shintaro; Fujimoto, Mitsuo; Kamimuki, Kenichi (MDPI AG, 2020-06-07)
      Refill friction stir spot welding (RFSSW) is an emerging technology for joining aerospace aluminum alloys. The aim of the study is to investigate the effects of the refill friction stir spot weld spacing and the edge margin ...
    • An engineering approach to analyze damage initiation modes in tapered composite structures 

      Rao, Prabhakar M.; Palliyaguru, Upul R.; Gurvish, Mark R.; Seneviratne, Waruna P. (DEStech Publications Inc., 2018)
      In this work an engineering approach is demonstrated for analyzing damage initiation modes in tapered composite structures. The analysis methodology includes simulation of the non-linear static response of tapered composite ...
    • Evaluation of ls-dyna mat162 for modeling composite fastener joints for high rates of loading 

      Kona Ravi, Aswini; Bhasin, Akhil; Gomez, Leandro; Olivares, Gerardo; Gomez, Adrian; Keshavanarayana, Suresh R.; Pang, Jenna K.; Molitor, Matthew; Rassaian, Mostafa (American Institute of Aeronautics and Astronautics Inc., 2019-01)
      In the present work, the behavior of composite-fastener joints in bearing failure at dynamic stroke rates of 500 in/s, 300 in/s and 100 in/s has been evaluated through progressive damage analysis (PDA) material model in ...
    • Fatigue damage modeling in laminated composites by using Rx-FEM and strength tracking method 

      Lu, Weitsen; Gao, Zhenjia; Adluru, Hari K.; Hoos, Kevin H.; Seneviratne, Waruna P.; Mollenhauer, David H.; Iarve, Endel V. (DEStech Publications, 2021-09)
      The durability and residual load carrying capacity of composite materials and structures is of critical importance for increasing their application across the industry. Regularized eXtended Finite Element Method (Rx-FEM) ...
    • High rate testing of composite fastener joints with and without clamp-up 

      Gomez, Adrian; Keshavanarayana, Suresh R.; Castillo, Luis D.; Kona Ravi, Aswini; Bhasin, Akhil; Pang, Jenna K.; Molitor, Matthew; Rassaian, Mostafa (DEStech Publications Inc., 2018)
      The NASA Advanced Composites Consortium (ACC) High Energy Dynamic Impact (HEDI) group has been investigating experimentally the effects of testing speed and fastener clamp-up on the behavior of single lap shear composite ...
    • Injection repair for restoration of composite properties 

      Seneviratne, Waruna P.; Saathoff, Brandon L.; Palliyaguru, Upul R.; Hayes, B.S.; Dixon, D.G. (SAMPE, 2019-03)
      Resin injection is a less intrusive method of repair and does not require near the post processing of other composite repair methods. However, until recently this method of repair has not allowed the restoration of the ...