A device for evaluating quality of welding spots of a panel is disclosed. The device includes a vibration transferring member, a first access member contacted with one surface of one end portion of the vibration transferring member and with the one surface of the panel, a second access member contacted with one surface of the other end portion of the vibration transferring member and with the one surface of the panel, an oscillator for supplying vibration to the one end portion of the vibration transferring member, a sensor disposed on the vibration transferring member to detect characteristic of vibration transferred along the vibration transferring member, and a computing device for analyzing characteristic of the welding spots using characteristic of vibration detected in the sensor.

A system for ultrasonic examination of spot welds comprising a probe, a computer, and a display screen, the computer configured for spot weld analysis by appropriate analytical software, the probe for coupling to a spot weld via a couplant, wherein the probe comprises a two dimensional array of sensors that is each configured to conduct an A scan analysis, thereby providing a color pixel indicating weld quality in terms of parameters selected from the group of size, shape, voids, upper sheet-weld nugget interface strength and lower sheet-weld nugget interface strength, such that the two dimensional array of sensors produces a two dimensional pixilated image indicating the weld quality in terms of selected parameters.

Techniques for reducing or eliminating cross talk in row-column addressed array (RCA) probes are described. A diode can be connected in series to piezo-composite element in each pixel of the RCA to prevent cross talk. A resistor can also be provided in parallel to the piezo-composite element for discharging purposes and providing DC paths for the forward and backward bias voltages to the diodes. Thus. RCA probes using the techniques disclosed herein can use sub-apertures for, among other things, inspecting longitudinal and transverse flaws, and for more efficient local focusing for an acoustic camera without significant cross talk interference.

According to one embodiment, a control device controls a welding device performing resistance welding. When an inspection value satisfies a first condition, the control device modifies a setting value for the resistance welding and causes the welding device to perform the resistance welding. The inspection value is obtained by an inspection of a weld zone formed by the resistance welding. The control device does not cause the welding device to perform the resistance welding when the inspection value satisfies a second condition.

A method and apparatus for ultrasonic in-process monitoring and feedback of resistance spot weld quality uses at least one transducer located in the electrode assembly transmitting through a weld tip into an underway weld. Analysis of the spectrum of ultrasonic waves provides the operator with an indication of the size, thickness, location, dynamics of formation and quality of the spot weld. The method presents a fundamentally new physical approach to the characterization of the spot weld quality. Together with transmission mode it includes new modes of operation of ultrasonic probes such as a reflection mode and simultaneous use of transmission and reflection modes, and a new physical interpretation of the signal analysis results.

A spot-welding electrode assembly includes an electrode, an electrode cap at an outer end of the electrode, and a plurality of transducer elements positioned inward of the electrode cap. The transducer elements may be micro-elements. A method for monitoring a weld formed by a spot-welder includes passing current from an electrode assembly through a stack-up, transmitting an ultrasonic wave from each of a plurality of sources in the electrode assembly to a plurality of points in the stack-up, and monitoring the ultrasonic waves to monitor the weld formation.

Automated real-time characterization of resistance spot welds using ultrasound-based nondestructive evaluation requires a computational process and system to accurately and rapidly interpret the ultrasonic data in real time. Such a process can be automatically learned using artificial intelligence, from a dataset of exemplary ultrasonic data from nondestructive evaluation of resistance spot welds for which a corresponding ideal evaluation of each weld is provided. The process can then be implemented into a system to automatically interpret data from non-destructive evaluation in real-time. The ideal evaluation of each weld requires identification a large set of features that are observable in the ultrasonic signature and comprehensively characterize the corresponding weld process.