Patents Represented by Attorney Roger H. Chu
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Patent number: 8306793Abstract: Methods and systems for simulating acoustic field resulted from particular excitations by performing vibro-acoustic analysis of a structure are disclosed. According to one aspect of the present invention, vibro-acoustic analysis of a structure is performed in two stages. First, steady state dynamic (SSD) responses are obtained using a finite element analysis model of a structure subject to harmonic excitations (e.g., external nodal loads, pressures, or enforced motions (e.g., ground motions), etc.). The steady state responses are the results (e.g., nodal velocities at desired locations of the structure) obtained in a finite element analysis in frequency-domain. Second, an acoustic analysis is conducted according to Helmholtz equation using the nodal velocities obtained at desired locations on the structure as a boundary condition. The acoustic analysis can be performed in a number of procedures (e.g., boundary element method, Rayleigh approximation method, etc.).Type: GrantFiled: September 14, 2010Date of Patent: November 6, 2012Assignee: Livermore Software Technology CorporationInventors: Yun Huang, Mhamed Souli, C. Cleveland Ashcraft
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Patent number: 8296109Abstract: Methods and systems for enabling simulation of material aging effect of chrono-rheological materials in computer aided engineering (CAE) analysis are disclosed. According to one aspect, a set of material property tests is conducted for a chrono-rheological material of interest. Each test obtains a series of material properties such as relaxation test data at different age. The relaxation test data are measured by maintaining a specimen of the chrono-rheological material at a predetermined strain. A set of first and second time-dependent material aging effect parameters is determined by shifting and matching the series of relaxation test data between each pair of the tests.Type: GrantFiled: April 20, 2009Date of Patent: October 23, 2012Assignee: Livermore Software Technology CorporationInventors: William W. Feng, John O. Hallquist
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Patent number: 8271237Abstract: Improved 8-node hexahedral elements configured for reducing shear locking in finite element method are disclosed. According to one aspect, aspect-ratio based scale factors are introduced to modify partial derivatives of the isoparametric shape function of the hexahedral element with respect to isoparametric dimensions, respectively. The modified derivatives are used for calculating the Jacobian matrix thereby the rate-of-strain. The scale factor is configured such that no changes for a perfect cubic solid element (i.e., element having aspect ratio of 1 (one) in all three spatial dimensions), while significant changes for element having poor aspect ratio. In other words, elements with poor aspect ratio are mapped to a perfect cubic element using the aspect-ratio based scale factors. According to anther aspect, off-diagonal components in the local Jacobian matrix are directly modified by cancelling terms related to spurious shear deformation modes.Type: GrantFiled: February 2, 2010Date of Patent: September 18, 2012Assignee: Livermore Software Technology CorporationInventor: Thomas Borrvall
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Patent number: 8209157Abstract: Methods and systems for simulating beam-to-surface contacts in finite element analysis (FEA) are disclosed. A FEA model contains at least one beam element and at least one surface mesh. Surface mesh comprises a plurality of two-dimensional finite elements having arbitrary mesh density. A minimum characteristic length (CL) of the surface mesh is calculated. One or more interior points are defined for those beam elements with length longer than CL. For every nodal point (i.e., end nodes and interior points if any), a parametric coordinate between 0 and 1 inclusive is established and kept constant throughout the FEA analysis. Distributed nodal masses are used for calculating a stiffness value for calculating nodal force to resist penetration.Type: GrantFiled: August 21, 2009Date of Patent: June 26, 2012Assignee: Livermore Software Technology CorporationInventor: John O. Hallquist
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Patent number: 8200464Abstract: Systems and methods of simulating an explosion in time-marching finite element analysis are disclosed in the present invention. A method is configured for increasing user (e.g., engineer or scientist) productivity by reducing computation time of simulating fluid-structure interaction due to an explosion. The method comprises a creation of a finite element analysis model that includes structure, surrounding fluid, a blast source of the explosion and a single layer of ambient elements each having a segment representing a boundary of the fluid facing the blast source. Each ambient element is associated with a particular finite element representing the fluid at the boundary. The ambient elements are configured to be situated between the blast source and the structure such that the simulation can be carried on a set of boundary conditions specified thereon. The boundary conditions comprise a set of nodal velocities that are determined from the empirical formula (e.g., Friedlander equation).Type: GrantFiled: October 21, 2009Date of Patent: June 12, 2012Assignee: Livermore Software Technology CorporationInventor: Todd Patrick Slavik
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Patent number: 8200458Abstract: Improved methods and systems for defining and creating simulated rigid bodies in finite element analysis are disclosed. One or more rigid finite elements in a finite element model are designated for forming one or more simulated rigid bodies (RBs). Each simulated RB comprises an arbitrary number of rigid finite elements connecting to one another in an arbitrary shape. Each simulated RB is created by locating all of the elements embedded in the model through shared node or nodes. A procedure of using element definition as a guide to set up an array of node flags, each node flag for one node such that all RBs defined in the model can be located efficiently. Once all RBs have been located, each unique RB is defined as a unique list of connected rigid finite elements.Type: GrantFiled: December 17, 2009Date of Patent: June 12, 2012Assignee: Livermore Software Technology CorporationInventors: John O. Hallquist, Brian Wainscott
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Patent number: 8190408Abstract: Methods and systems for numerically predicting surface imperfections on stamped sheet metal parts are disclosed. FEM mesh includes a plurality of shell elements and a plurality of nodes that represents a stamped sheet metal part. At least one surface of the part needs to be examined for imperfection, which can be used for adjusting the die for forming the sheet metal part. Each surface is created by fitting all of nodes of a portion of the FEM mesh in a group-to-group scheme. A group is defined to include a center element and its neighbors. Neighbor elements share a side with the center element are always included in the group. Each group includes at least three neighbors in additional to the center element. Node-sharing elements are added into the group such that the criterion of at least three neighbors is met.Type: GrantFiled: March 22, 2010Date of Patent: May 29, 2012Assignee: Livermore Software Technology CorporationInventor: Xinhai Zhu
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Patent number: 8180605Abstract: Improved systems and methods of creating a smooth contact-impact interface (i.e., a curve fitted surface) in finite element analysis are disclosed. According to one aspect, a smooth contact interface is created for a master segment used for simulating contacts. First, for every nodal point in the master segment, a list of elements that share at least the node is determined. Then a nodal normal vector is calculated using a weighted average of respective element normal vectors of all elements in the list. The calculated nodal normal vector is adjusted for special edge effect, which is an intersection between flat and curved geometries. A set of edge control points are created using a pair of adjacent corner nodes. A mid-element control point is further created for quadrilateral shell elements. The smooth contact interface is configured to encompass all corner nodes and all of the control points.Type: GrantFiled: May 19, 2009Date of Patent: May 15, 2012Assignee: Livermore Software Technology CorporationInventor: Xin-Hai Zhu
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Patent number: 8165856Abstract: Improved methods and systems for a neighborhood determination in computer aided engineering analysis are disclosed. According to one aspect, a list of neighbor elements is created for a base element of a grid model representing a structure or an engineering product. The representative node's coordinates of the base element are calculated using corner nodes of the base element. A characteristic length is assigned to the base element. The characteristic length can be determined by users of the computer aided analysis, or be calculated using geometry of the base element. The characteristic length and the representative node collectively define a surface boundary that divides elements in the grid model into two groups. The first group contains potential neighbors, while the second group contains non-neighbors.Type: GrantFiled: July 6, 2009Date of Patent: April 24, 2012Assignee: Livermore Software Technology CorporationInventor: Tushar Goel
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Patent number: 8150668Abstract: Simulation of thermal fluid-structure interaction using bulk flow fluid elements (BFFEs) is described. Each BFFE is configured to include the following characteristics: 1) at least one surrounding layer of solid elements representing either the surrounding structure or the pipe wall; 2) a layer of shell elements or Bulk Node Segments representing the outer boundary of the fluid; 3) a Bulk Node at the center of the BFFE for defining fluid properties (e.g., density, specific heat) and volume (i.e., fluid volume is calculated as the enclosed volume between the Bulk Node and all of the Bulk Node Segments that surround it); 4) a fluid flow beam element or Bulk Node Element for defining fluid flow path to another BFFE; and 5) a contact interface between the solid elements and the shell elements for conducting fluid-structure thermal interaction.Type: GrantFiled: February 11, 2009Date of Patent: April 3, 2012Assignee: Livermore Software Technology CorporationInventor: Arthur B. Shapiro
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Patent number: 8126684Abstract: Improved topology optimization for engineering product design is disclosed. An engineering product including a design domain to be optimized is defined. Design domain can be a portion or the entire engineering product. Design objective and optional constraint are defined such that optimization goal is achieved. Additionally, initial configuration of the design domain is represented by a finite element analysis (FEA) mesh. Each element or element group is associated with a design variable. A set of discrete material models is created from the baseline material used for the design domain. The set of discrete material models is configured to cover entire range of the design variable and each discrete material model represents a non-overlapping portion. Each element representing the design domain is associated with an appropriate discrete material model according to the design variable. Structure response is obtained via FEA to evaluate design objective and update design variable.Type: GrantFiled: April 10, 2009Date of Patent: February 28, 2012Assignee: Livermore Software Technology CorporationInventors: Tushar Goel, Willem J. Roux
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Patent number: 8106279Abstract: Wind musical instrument moisture drying devices are disclosed. According to one embodiment, the drying device comprises a fan unit containing a fan mounted on a motor housed in an enclosure having opposite first and second ends, the fan is located within the enclosure near the first end and is configured for drawing air flow from the second end toward the first end while in operation, an electric energy source coupled to the fan unit via a cable, and an adjustable adapter radially coupled to outer perimeter of the enclosure of the fan unit, the adjustable adapter is so configured to be fit over an opening of the wind musical instrument's tubular body, where moistures accumulated inside the wind musical instrument are desired to be dried by the moisture drying device, which is deployed into the tubular body by inserting the fan unit into the opening.Type: GrantFiled: August 6, 2010Date of Patent: January 31, 2012Inventor: Shun-Hwa Chang
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Patent number: 8078794Abstract: Hybrid solid state drives (SSD) using a combination of single-level cell (SLC) and multi-level cell (MLC) flash memory arrays are described. According to one aspect of the present invention, a hybrid SSD is built using a combination SLC and MLC flash memory arrays. The SSD also includes a micro-controller to control and coordinate data transfer from a host computing device to either the SLC flash memory array of the MLC flash memory array. A memory selection indicator is determined by triaging data file based on one or more criteria, which include, but is not limited to, storing system files and user directories in the SLC flash memory array and storing user files in the MLC flash memory array; or storing more frequent access files in the SLC flash memory array, while less frequent accessed files in the MLC flash memory array.Type: GrantFiled: October 29, 2007Date of Patent: December 13, 2011Assignee: Super Talent Electronics, Inc.Inventors: Charles C. Lee, David Q. Chow, Abraham Chih-Kang Ma, I-Kang Yu, Ming-Shiang Shen
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Patent number: 8069017Abstract: In one aspect of the invention, each bolt is modeled using a beam element in a FEA model. To apply desired pretension to one or more bolts, at least one pretension-versus-time curve is specified. Each pretension-versus-time curve includes ramp portion, desired pretension portion and optional unloading portion. Duration of the pretension-versus-time curve generally covers first 0.5-1% of total simulation time of a car crashworthiness analysis. Ramp portion starts from zero to desired pretension in a substantially linear manner, and hence being configured for applying desired pretension to a bolt gradually with smaller increments. Desired pretension portion is configured for ensuring the desired pretension can actually be applied to the beam element during an initialization process—a series of quasi-static analyses. Since the method is independent of the deformation of the beam, the method completely avoids the need to iteratively determine an axial strain or displacement that gives the desired pretension.Type: GrantFiled: September 25, 2008Date of Patent: November 29, 2011Assignee: Livermore Software Technology CorporationInventor: John O. Hallquist
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Patent number: 8061437Abstract: A nail gun with a rapidly attachable and detachable magazine assembly includes a nail gun, a magazine assembly and a quick joining mechanism. A handle portion of the nail gun has a quick joining pillar adapted to engage with the quick joining mechanism to attach the magazine assembly to the nail gun. By simply snap-fitting the quick joining pillar into a fixing element of the quick joining mechanism, the quick joining mechanism can naturally fix the quick joining pillar into the fixing element, and thus, the magazine assembly can be attached to the nail gun by simply a single action. Moreover, by pulling a pull rod of the quick joining mechanism and withdrawing the quick joining pillar from within the fixing element, the magazine assembly can be attached from the nail gun by also simply a single action.Type: GrantFiled: March 4, 2010Date of Patent: November 22, 2011Assignee: De Poan Pneumatic Corp.Inventor: Chia-Sheng Liang
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Patent number: D652378Type: GrantFiled: January 28, 2011Date of Patent: January 17, 2012Inventor: ZhuoWen Liao
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Patent number: D660819Type: GrantFiled: January 4, 2012Date of Patent: May 29, 2012Assignee: AmRoad Technology Inc.Inventors: Ren-Peng Chen, Ke-Rong Lin
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Patent number: D669904Type: GrantFiled: July 6, 2011Date of Patent: October 30, 2012Assignee: Super Talent Electronics, Inc.Inventors: Jim C. Ni, XuLin Cao
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Patent number: D669996Type: GrantFiled: April 24, 2012Date of Patent: October 30, 2012Assignee: Vicon Healthcare International Inc.Inventor: Jung-Shang Chen
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Patent number: D671123Type: GrantFiled: July 6, 2011Date of Patent: November 20, 2012Assignee: Super Talent Electronics, Inc.Inventors: Jim C. Ni, XuLin Cao