Advanced Material Failure Modeling
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VistaMat Suite was developed by Thornton
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VistaMat Suite
Tomasetti’s Weidlinger Applied Science practice to
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VistaCal
facilitate efficient, high-fidelity advanced material
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VistaDam
failure modeling for industrial applications.
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VistaFire
The suite comprises three software modules –
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Market Sectors
VistaCal, VistaDam and VistaFire – that integrate
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Usage, System Requirements & Development
directly into many commercial finite-element packages, including LS-DYNA and SIMULIA Abaqus.
VistaMat Suite is rooted in fundamental research conducted by Thornton Tomasetti’s Weidlinger Applied Science practice in support of several multiyear Office of Naval Research programs. This research led to the development of new types of constitutive models, which were transitioned to the U.S. Navy to benefit ship design and certification. They have been incorporated into a number of commercial explicit finite-element solvers, such as LS-DYNA and Abaqus, and packaged into three software modules: VistaCal allows automated data processing and calibration of multiple advanced-plasticity and ductile-fracture models (e.g., Johnson-Cook, GISSMO, VistaDam, VistaFire). VistaDam, an advanced, three-invariant plasticity and fracture model, facilitates reliable and efficient ductile-fracture prediction for large-scale shell structures. VistaFire uses a thermomechanical constitutive model to simulate the behavior of structures exposed to fire and other thermomechanical loads. 4
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VistaCal is a calibration software tool for plasticity and fracture models used in the analysis of crashes and other extreme events. VistaCal substantially reduces the cost of material characterization and model calibration and improves the accuracy of the material cards, which can result in vehicle weight reduction. VistaCal pairs seamlessly with a variety of commercial finite-element codes, including LS-DYNA and Abaqus. In addition to enabling model calibration, VistaCal serves as a data repository and uncertainty-quantification platform. It can compare past and present fits, calculate uncertainty-quantification metrics or serve as a library of material cards and associated experimental test data.
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Material constitutive calibrator.
Alsos, 2009
Left: Top: Bottom:
Simulation of weld fracture Fracture observed in test VistaDam fracture prediction
VistaCal features a simple and intuitive graphical interface that enables users to upload data, automate processing, identify the most appropriate hardening curve, solve optimization problems to determine the material model parameters, view the results and export material cards. The broad applicability of VistaCal makes it an important tool, especially for the automotive and aerospace industries. It automates and standardizes a crucial component of every crash and failure simulation: material model calibration. This capability, along with its integrated historical data repository and uncertainty-quantification platform, makes VistaCal a useful tool for any material and structural design process performed by means of finite-element simulation.
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Material constitutive calibrator.
Left: Top: Bottom:
VistaCal graphical user interface Ductile fracture in metals VistaCal repository of material fits
Š Kovaleff | Dreamstime.com
VistaDam is a ductile-fracture prediction module whose shell-based approach represents the cutting edge in ductile-fracture mechanics for large-scale, thin-walled structures. Reliable structural-scale fracture modeling restricts the finite elements used in the analyses to shell elements. VistaDam was developed based on a comprehensive constitutive formulation embedded in the shell-mechanics framework. This formulation features a three-invariant plasticity model that accounts for dependence of the strain at fracture on both stress triaxiality and the third invariant of the deviatoric stress, which has a significant influence on shear-dominated fracture. VistaDam achieves high levels of accuracy in fracture prediction while maintaining discretization levels and computational efforts that are realistic for structural applications. Its consistent calibration and validation framework significantly reduces the experimental effort necessary to calibrate models.
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Ductile fracture prediction.
Giagmouris, 2010
Giagmouris, 2010
Left: Top: Bottom:
VistaDam tube-crushing simulation Fracture observed in test VistaDam fracture prediction
VistaDam has been extensively validated for a variety of thin-walled metal structures, and through a series of hydrostatic buckling tests of submerged cylinders. All investigated cases involved complex fracture mechanisms with significant mode interaction, including through-thickness fracture (mode III). Simulations of both controlled static and fast dynamic events involving explosive loads demonstrated excellent correlation with experimental test results. A series of automotive crash scenarios were also investigated based on component-level experimental tests. Multiple geometries and impact velocities were considered, including rocker beams, and B pillars. VistaDam simulations were conducted using several different meshes to verify the objectivity of the solution. All considered cases demonstrated excellent agreement with experimental test results, validating the theoretical foundations of VistaDam.
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Real-world applications.
Left: Top: Bottom:
VistaDam component simulation Fracture observed in test VistaDam fracture prediction
VistaFire is a thermomechanical analysis module for predicting fire effects on structures, including their residual capacity. It focuses on large-scale structures and their response to transient dynamic loading conditions. The VistaFire module employs a unified computational approach to evaluate the operational capacity of structures exposed to extreme thermomechanical loads with widely varying stresses, temperatures and strain rates. VistaFire was developed based on a comprehensive viscoplasticity model embedded in the shell mechanics framework. It is unique in its ability to represent both creep deformation and fast dynamic response to impulsive loads. VistaFire has been extensively validated against data from a variety of experimental tests, including a series of tensile creep tests, buckling tests conducted for both coupon and subcomponent levels with varying temperatures, and burn-through tests. In all cases, excellent correlation with the test data was achieved.
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Fire effects on structures.
Rippe et al., 2013
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WTC 2 collapse from impact and fire Burn-through component test VistaFire burn-through simulation
AUTOMOTIVE: Growing demand for lightweight vehicles has increased the need for thinner-grade materials that meet or exceed current crash-performance levels. This requires effective fracture-prediction capabilities that facilitate detailed investigation of vehicle components beyond forming limits. VistaMat modules – especially VistaCal – are optimally designed to meet these needs while preserving the practicality of modeling on a structural scale and efficiently calibrating the models against a small set of coupon-level tests. AEROSPACE: While the aerospace industry is primarily concerned with fatigue-related cracking, many ductile-fracture problems require investigation of plasticity preceding fracture initiation. VistaMat modules can be used for investigation of impact and containment problems (e.g., turbine blade blowout). Fire and other thermomechanical loading conditions are of particular concern for the aerospace industry. Accurate representation of creep, and progressive failure analysis, facilitated by VistaFire, could significantly improve the effectiveness of computational tools used in this industry.
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Market sectors and applications.
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WTC 1 collapse investigations Automotive crashworthiness testing Automotive crash simulation
Usage, System Requirements & Application Development VistaMat modules may be purchased individually or as a package. The purchase price of VistaMat Suite or any of its modules includes a user manual and code maintenance and telephone/email support from the technical development team for the duration of the license agreement. Special arrangements may be made, based on mutually agreeable terms.
System Requirements
Consulting
VistaMat modules are not stand-alone programs. Rather, they operate under
VistaMat’s team of engineers, scientists and software developers can provide consulting services to industrial and government institutions interested in developing solution methodologies for challenging engineering problems. Developed technology will be implemented into VistaMat Suite as modular software and transitioned as part of the deliverable product.
the control of general finite-element solvers (e.g., Abaqus, LS-DYNA). System requirements are therefore dependent on the specific software operated by the user and set by the developer of the solver.
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40 Wall St. | New York, NY 10005-1304 Phone: 212.367.2983 | Email: contact@vistamat.com | Web: www.vistamat.com