Structural Engineering and Advanced Analytical Modeling
LINKING THEORY AND PRACTICE
DESIGN | CONSTRUCTION | OPERATIONS | RELIABILITY | SAFETY | SECURITY
ANATECH CORPIn 2013, we expanded our engineering expertise by joining Structural Integrity Associates, Incorporated. ANATECH Corp., that you’ve known for 35 years, is now ANATECH Corp., a wholly owned subsidiary of Structural Integrity Associates, Inc.® This brought our engineering leadership together to provide more innovative and integrated client solutions while maintaining our core expertise in Structural Engineering, Advanced Structural Analysis, Nuclear Fuel and Reactor Technology.
WHO ARE WE?ANATECH Corp., a Structural Integrity Associates, Inc. Company, is a consulting engineering firm based in San Diego, California. We provide services in the expert application of state-of-the-art analytical methods to both large civil infrastructure and nuclear engineering systems.
STRUCTURAL ENGINEERINGOur Structures division is highly experienced in providing structural engineering support and advanced structural analysis for our clients. We are experienced in complex nonlinear analysis of concrete and steel structures subjected to normal operating loads and beyond design basis loads involving thermal, seismic, and impact scenarios. We also specialize in advanced modeling for performance based analyses necessary for establishing ductility, failure modes, root cause, limit states and structural fragility. These applications span a wide range of civil structures, including long-span bridges, buildings, dams, navigational hydraulic structures, nuclear containments and related structures, heavy-lift cranes, and spent fuel handling and storage systems.
NUCLEAR FUEL AND REACTOR TECHNOLOGYIn Nuclear Fuel and Reactor Technology, our Fuels division is highly experienced in performance evaluations, material modeling, and engineering analysis of nuclear fuel behavior under normal operating conditions, off-normal transients, and postulated accidents. We have unique experience in all aspects of fuel reload design including core neutronics, thermal-hydraulics, transients and radiological dose analyses. Recognizing the importance of component quality on fuel performance and reliability, we have developed advanced capabilities in the technical assessment and fabrication surveillance of fuel rods and assembly components.
OUR MISSIONThe mission of our Structure’s Group is to provide practical and innovative engineering services and advanced analytical modeling for structural engineering design, construction, operations, reliability, safety and security. With more than 35 years of direct experience in the performance assessment, and safety analysis of plain, reinforced and pre/post-tensioned concrete and steel structures, we have peer-recognized competence and experience for providing independent engineering analysis services to the A/E industry. This includes nonlinear static thermal-mechanical stress analysis, implicit dynamic time history seismic evaluations, and explicit dynamic extreme blast and impact loading events to assess structural performance of new designs, as-built vulnerabilities, efficacy of retrofit modifications, and root cause failure analysis. The applications include a wide range of structures, such as bridges, buildings, dams, navigational hydraulic structures, nuclear containments and related structures, cranes, and spent-fuel handling and storage systems.
Advanced analytical techniques must rely on material modeling and computational simulation methods that are capable of predicting severe damage states and structural failures. The development of such advanced methods have been a continuous activity at ANATECH for nearly four decades. At the core of the methodology is the ANACAP Concrete constitutive material model, incorporating the unique characteristics of concrete as a time-evolving structural material, which include: multi-axial cracking, compressive crushing, strain softening, concrete-reinforcement interaction, aging, creep, shrinkage and time-temperature degradation of strength and stiffness. Consistent with the finite-element methodology, the material constitutive relations are formulated at the element integration points, and as such the model supports all standard finite element types such as beams, shells, and two- and three-dimensional solids.
With the ANACAP model, we provide several levels of modeling capabilities: ranging from a simple cracking model suitable of quasi-linear design analysis to a complex model intended for highly non-linear response regimes, including aging, creep, and extensive cracking/crushing leading to severe damage and structural failure.
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ANACAP CONCRETE CONSTITUTIVE MATERIAL MODELOur ANACAP concrete model is based on smeared-cracking methodology incorporating the unique characteristics of concrete as a structural material including:
■ Multi-Axial Cracking• Cracks form perpendicular to direction of largest tensile strain.• Multiple cracks at integration point, mutually orthogonal.• Upon crack formation, normal stress across crack reduced to zero.• Crack remains fixed and can never “heal”.• Crack can close, resist compression and shear, and re-open under
load reversal. ■ Post Cracking Shear Behavior
• Shear modulus in plane of crack reduced to 40% of initial value when crack forms.
• Normal strain to crack primary variable affecting shear transfer mechanism.
• Shear stiffness further reduced with opening strain normal to crack.• Shear shedding feature reduces numerically accumulated shear
stress across an open crack as crack continues to open. ■ Compressive Crushing and Strain Softening ■ Cyclic Degradation ■ Young Concrete Aging, Creep and Shrinkage ■ Aging Structures, Degradation of Strength and Stiffness ■ Thermal Dependence – High Temperature Softening ■ Pre-Cracking and Crack Pressurization ■ Extensive Pedigree of Peer Review and Experimental Validation
ADVANCED FINITE ELEMENT ANALYSIS CAPABILITIESWe have over 35 years of experience developing and applying state of the art structural analysis techniques to a wide range of structures and components.
■ Seismic and Dynamic Analyses, Modal Dynamics, Response Spectrum Analysis, Non-Linear Time History, Eigenvalue Buckling.
■ Coupled Thermal-Stress Analyses, Incremental Construction with Heat of Hydration, Residual Stress Distributions at Welded Connections, Thermal Cycling.
■ Fluid-Flow Analyses, Hydrodynamic Loads, Fluid-Structure Interaction, Development of Flow Velocities and Distributions.
■ Reliability Evaluations, Develop Response Surfaces and Performance Limit States, Probabilistic Sampling.
■ Explicit Dynamic Analysis, High Energy Blast Loads, Aircraft Impact Assessment, Heavy Equipment/Load Handling Accidents.
■ Fatigue and Fracture Mechanics, Remaining Fatigue Life, Crack Initiation and Brittle Failure, Ductile Crack Growth Rate, J-Integral Methods for Stress Intensity.
ADVANCED FINITE ELEMENT MESH GENERATION CAPABILITIES
■ Geometry provided by the client is used as basis for constructing the finite element model, ensuring the highest possible quality and precision of the final product.
■ Geometric data can be refined and subdivided as needed to allow for maximum customization of the finite element mesh.
■ Customized, manually-built meshes allow for maximum analytical functionality. This approach allows for close control of meshing intricate or complex geometric features.
ANALYTIC SUPPORT AND CONSULTING SERVICES FOR STRUCTURAL DESIGN
■ Design Verification through F.E. Modeling ■ Develop and Evaluate Assembly Specifications ■ Design and Evaluation of Structural Detailing and Concrete Reinforcement
■ Checking and Independent Reviews in Accordance with ACI, AISC, and ASME Codes.
■ P.E. Coverage in Most States
ANALYTIC SIMULATION FOR STRUCTURAL PERFORMANCE DURING CONSTRUCTIONWe are highly experienced in performing Nonlinear Incremental Structural Analysis (NISA) of massive concrete structures and is recognized in USACE NISA Guidance, ETL 1110-2-365. The NISA methodology evaluates thermal induced cracking by calculating time dependent thermal gradients relative to the restraints against thermal expansion in the structure. The constructability study requires a complex, coupled thermal-stress analysis procedure and nonlinear material properties taking into account the time varying temperature distributions dependent on the volume and rate of concrete placement, the sequence and geometry of the placements, concrete placement temperature and heat generation rate, and the ambient conditions and thermal environment. At the same time, the restraint in the structure depends on the sequence and geometry of the placements, boundary restrains, and the time dependent aging, creep, and shrinkage properties of the concrete being placed. The analytic simulation tracks the history of the material behavior from a few hours of age until approximately one year after final lift placement.
■ Optimization of Mass Concrete Construction ■ Mitigation of Thermal Induced Cracking ■ Variations in Design Parameters and Materials ■ Effects of Residual Stresses in Welded Connections
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ANALYTIC MODELING IN SUPPORT OF OPERATIONS, STRUCTURAL REPAIRS, OR FIELD OPERATIONS
■ Fatigue Life Evaluation ■ Evaluate In-Situ Structural Behavior ■ Evaluate Performance of Field Modifications ■ Design, Evaluate and Verify Efficacy of Retrofit Modifications
FINITE ELEMENT MODELING FOR STRUCTURAL RELIABILITY EVALUATIONS
■ Best Estimate Analysis for Performance Baseline ■ Analytical Projections for Performance Limits ■ Develop Probabilistic Based Models ■ Probable Risk Assessment, Seismic Risk Assessment, Seismic Margin Assessment
■ Fragility Studies
ANALYTICAL MODELING FOR EVALUATION OF STRUCTURAL SAFETY
■ Performance Based Analysis ■ Margins for Loading Beyond Design Basis Events ■ Structural Life Extension and Aging Effects ■ Material Degradation over Time ■ Root Cause Evaluation of Structural Failure ■ Handling Accidents for Heavy Loads
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ANALYTICAL SIMULATION FOR SECURITY ISSUES
■ Structural Damage Due to High Energy Impact or Blast Loading• Tornado Generated Missiles• Terrorist Threats• Aircraft Impact Assessment
■ Evaluate Consequences of Progressive Failure ■ Develop Hardened Designs or Retrofits
QUALITY ASSURANCE AND SECURITYWe take pride in providing professional, timely, and accurate engineering consulting services for our clients. We have a strong track record of supporting our clients and presenting our work before any governing regulatory bodies. If required by client/project, our Quality Assurance Program meets the requirements and procedures in accordance with Title 10 of the Code of Federal Regulations Part 21, Part 50 Appendix B and ASME NQA-1, ASME Section III and other recognized national standards. Most of our staff have been granted Safeguard Information (SGI) Clearance by all of the primary Nuclear Vendors within the United States.
05 10 2016 Q300
San Jose, CA408-978-8200
State College, PA814-954-7776
San Diego, CA858-455-6350