magento2: how validation work in magento2

Try this:

require(["jquery"], function ($) {
    $(document).ready(function () {
        $('#my-button-name').click(function () { // The button type should be "button" and not submit
            if ($('#form-name').valid()) {
                alert("Validation pass");
                return false;
            }
        });
    });
});

Hope this helps!