Careers

Nonlinear Mechanics and Dynamics Research Institute

FEA modeling simulation

A test specimen for measuring dissipation across a lap joint under different loading environments (top), and Finite Element Analysis (FEA) predictions for the same system (bottom).

When offered

The six-week institute will begin on June 20, 2016, and will end on July 29, 2016.

Afterwards, participants will have an opportunity to present their research in an institute-organized symposium at the 2016 ISMA International Conference on Noise and Vibration Engineering. The conference will be held on September 19–21 in Leuven, Belgium.

Who can apply

Graduate students and early career researchers from the U.S. and international communities

Locations

Sandia/New Mexico and the University of New Mexico

About the institute

The 2016 Sandia National Laboratories Nonlinear Mechanics and Dynamics (NOMAD) Research Institute will bring together participants from around the world to work in small teams on projects germane to interfacial mechanics and jointed structures.

The institute’s goals are to help form long-lasting collaborations between national laboratories, academia, and industry and to make significant progress toward solving major challenges in the area of joints and interfacial mechanics.

The institute is open to graduate students and early career researchers from the United States and international communities.

Research projects

In keeping with the institute’s collaborative vision, the institute is soliciting proposals for research projects.

Proposed projects can be associated with a participant’s application. Proposals that pose separate research questions regarding interfacial mechanics and jointed structures are also welcome. Each research topic should be able to capture a research team’s interest and should be of sufficient scope and breadth so that a team can make significant progress during the six-week session of the institute.

Some of the experimental and high-performance computational facilities at Sandia/New Mexico and the University of New Mexico will be available for use by teams in the institute. The projects currently planned for the institute include:

  • Experimental Assessment of Jointed Interface Configurations
    Instead of numerically modeling the effects of changing an interface's geometry, this project will experimentally characterize the effects of several different permutations of the same interface in order to partly determine the effect of the interface's design on joint stiffness and damping.

  • Measurement of the Effects of the Far-Field Structure on Joint Properties
    Using the transmission simulator method, this project will test Al Ferri's hypothesis that the far field structure helps determines the properties of a joint. Several different configurations will be measured in which the joint and near field structure are all the same as the Brake-Reuss beam. The far field structure will be modified to have stiffness and mass elements inserted.

  • Round Robin of Numerical Techniques for Nonlinear Structural Dynamic Response
    A continuation of the numerical round robin from 2014 and 2015. The goal this year is to use existing measurements from a clamped-free experiment to predict the response of the Brake-Reuss beam when it is only supported by bungees.

  • Interface Reduction Methods for Substructuring
    A theoretically based project, this focuses on using interface constraint modes to develop a new reduced order model basis that could potentially replace Craig-Bampton for jointed structures.

  • Random Sampling Strategy for Robust Contact Parameter Tuning
    The goal of this project is to extend and apply an objective method for contact parameter tuning based on a sampling technique that produces a large number of solutions on the basis of randomized extractions of contact parameters between given interfaces. Experimental data will be provided by AERMEC, the software for the dynamic simulation of the damper will be provided by AERMEC, and the goal of the project team is to develop the tuning software.

  • Extracting Material Responses from Kolsky bar Tests via Numerical Simulations
    The goal of this project is to use both dynamics and solid mechanics to conduct numerical simulations of the split Hopkinson bar tests with the objective of extracting the true stress-strain curve of the specimen. The current method involves a series of assumptions that do not have to be made if the complete test is modeled. The plan is to determine the stress-strain curve at high strain rates this way, and then to attempt to fit a Johnson-Cook type of model for the rate dependences of the material's response.

  • Emergent Homogenization Techniques and Effective Dynamical Properties
    There are various emerging homogenization techniques aimed at deriving a homogenized description of heterogeneous materials. These techniques include representative volume element, material with periodic structure represented by unit cell, and statistical volume element. How each of these methods influences the nonlinear material response remains an open question. A rigorous and quantitative comparison of these emerging homogenization techniques is required to answer important questions related to damage propagation, wave propagation in random media, and transport of oscillating fine scales.

  • Designing Brittle Fracture Specimens to Investigate Environmentally Assisted Crack Growth
    Brittle, bi-material specimens are being designed to investigate sub-critical crack growth at room temperature. The goal of this project is to use existing crack modeling software to design a series of new specimen that exhibit stable sub-critical crack growth at room temperature. If possible, an experimental result may be included in the final conference paper from this project.

  • Additive Manufacturing Topology Optimization Competition
    Using a project provided by the component design group, the goal of this project is to explore the role of local versus global optimization techniques as applied to topology optimization tools, including both Sandia's and Altair's. This project is focused on how you can design the topology optimization process, using pre-existing tools, to achieve a global minimum (i.e. minimize weight while constraining stresses and natural frequencies, then minimize stresses while constraining, etc.

  • Nonlinear System Identification for MEMS Devices
    Using existing MEMS devices, this project will focus on applying nonlinear system identification techniques to MEMS applications. Previously, success was demonstrated on using methods not previously applied to MEMS devices in order to characterize the nonlinearities built into them. This project will seek to more thoroughly explore these techniques and apply them to multiple MEMS devices.

  • Wireless Sensor Strategies for Structural Health Monitoring
    This project is focused on developing strategies for sensing under-platform impacts of a rail road bridge. The application of wireless sensors to this problem presents several unique challenges: the impact events are expected to occur with a frequency of once or twice per month. How are the sensors to be set up, then, in order to minimize energy drain while still detecting events with high confidence? Using cost-efficient strategies, there are two questions to answer: how much of the event can be recorded, and how severe are the events recorded?

Fees

There are no fees to register or participate in the institute. Participants will be responsible for their travel, housing, and daily living expenses, as well as any symposium-related costs.

Eligibility and requirements

  • All – An interest in working with other researchers from around the world to explore major challenges in the area of joints and interfacial mechanics.
  • Sandia internships for graduate students – U.S. citizenship, full-time enrollment status at an accredited college or university, and a minimum cumulative grade point average of 3.5/4.0. Learn more about Sandia’s internship requirements.

Application procedure

  • To apply to participate in the institute, email the following to Matthew Brake by March 1, 2016:
    • A copy of your curriculum vitae
    • A statement of your research interests
    • A statement indicating whether or not your home institution can provide funding for you to attend the institute.
  • To submit a research proposal for the institute, email your proposal to Matthew Brake by March 1, 2016.