Cylindrical,  cantilever beam, double-end fixed support beam and parallel beam are commonly used elastic element structures for load cells. Among them, cylindrical elastic elements (such as single cylindrical and single cylinder types) have the characteristics of simple and compact structure, good manufacturing processability and large rated range.  Beam-type elastic elements (such as cantilever shear beams, double-ended fixed shear beams and spoke-type) feature low height, good linearity, strong resistance to eccentricity and lateral loads, etc.  These structures are mainly used for measuring tensile or compressive loads. When it is necessary to simultaneously measure symmetrical cyclic tensile and compressive loads, the measurement requirements cannot be met due to the asymmetry of the sensitivity in the tensile and compressive directions or the inability to perform bidirectional loading.  To solve the measurement problem of symmetrical cyclic loads in the tensile and compressive directions, several load cell manufacturing enterprises such as BLH Company in the United States have successively developed tensile and compressive annular beam elastic elements with a series configuration of multiple strain beams.  It is to connect strain beams that generate normal stress or shear stress in series and configure them along the surface of a closed cylinder. External loads are applied to the strain beams through interleaved supports, making the tensile and compressive sensitivities basically consistent, to meet the requirement of simultaneously measuring symmetrical cyclic loads in the tensile and compressive directions. Among them, the elastic element characteristics of the annular shear strain beam are prominent and widely used.  There are three ways in which an external load is applied to an elastic element to generate shear stress: First, the external load is directly applied to the elastic element that generates shear stress, and the geometry of the strain zone of this elastic element should be able to obtain a greater shear strain than the bending deformation, such as cantilever shear beams, double-end fixed shear beams, etc.  Secondly, the moment generated by the load-bearing support causes the elastic element to undergo torsional deformation, resulting in shear deformation on the surface of the torsional elastic element and shear stress in its strain zone.  Thirdly, on both sides of the cylindrical elastic element, symmetrical square blind holes are respectively machined, and one diagonal of the square blind holes is consistent with the axis direction of the elastic element, while the other diagonal is perpendicular to the axis direction.  When the elastic element is loaded, shear stresses will inevitably occur in pairs on the two mutually perpendicular planes at the edge of its square blind hole. The magnitudes of the two are equal, and their directions are both perpendicular to the intersection line of the two planes and tend towards this intersection line together.  Due to the shear stress effect, the diagonals on the inner web of the square blind hole generate principal stresses and principal strains of equal magnitude but opposite directions, which fully meet the requirements for forming a Wheatstone bridge circuit. Usually, this method of generating shear stress is called the superimposed deformation method.  According to the different ways of generating shear deformation, the shear elastic elements of load cells can be classified into three groups: shear beam type, torsion type and superimposed deformation type.  The formation of the elastic element of the shear stress ring beam belongs to the shear beam type. That is, the ring beam is a strain beam formed by mechanical processing of multiple curved beams in series at the center of the cylinder. The external load causes the cylinder to undergo compression deformation through the flange plates with internal threads at both ends of the cylinder, and is then applied to the ring strain beam through the symmetrically and alternately arranged supports.  According to application requirements, annular strain beams that utilize normal stress can be formed, or annular strain beams that utilize shear stress can be formed.  The strain zone of the resistance strain gauge attached to the elastic element of the normal stress ring beam is mostly a rectangular cross-section, while the strain zone cross-section of the elastic element of the shear stress ring beam can be divided into rectangular and I-shaped.  By attaching the resistance strain gauge used for measuring normal stress or shear stress to the strain beam that generates normal stress or shear stress, a Wheatstone bridge circuit can be formed to complete the weighing and measurement task.  The distribution of shear stress in the strain zone of the elastic element of a shear beam depends on the shape of the cross-section.  When the shape of the strain beam is a rectangular cross-section, the shear stress is distributed according to a parabolic law, and the maximum shear stress on the neutral plane of the shear beam exceeds 1.5 times the average shear stress. The disadvantage is that pasting a resistance strain gauge in the area with the maximum parasitic stress will increase the nonlinear error.  A more reasonable approach is to use I-shaped cross-section strain beams, with the resistance strain gauges adhered to both sides of the I-shaped cross-section web plate. Due to the uniform shear stress distribution on the I-shaped cross-section web plate, the resistance strain gauges are located in a smaller parasitic stress zone. This not only enhances the sensitivity of the load cell but also provides excellent protection for the resistance strain gauges within the blind holes.  When the cross-sectional areas of the elastic elements of rectangular and I-shaped shear beams are the same, if their sensitivities are also the same, the I-shaped section has much greater resistance to bending and torsional moments than the rectangular section, thus reducing parasitic stress and measurement errors.  The elastic element of the annular shear beam developed by BLH Company of the United States is shown in Figure 1. The rigidity of beam 1 and beam joint 2 is the same, which reduces the rigidity of the elastic element and also causes a large bending parasitic stress.  To eliminate this defect, the elastic element developed by Siemens (Siemens) Company is shown in Figure 2. Four circular holes are machined parallel to the axis, thereby separating the deformed part of the beam and enabling the two ends of the resistance strain gauge 5 to be configured in the area with a smaller load.  Due to such a configuration, the error caused by the creep of the resistance strain gauge is reduced.  The square cross-section cylindrical shear beam elastic element developed by the National Institute of Measurement Technology of Hungary, as shown in Figure 3, has also achieved a similar purpose.  The disadvantage of the elastic element of the ring beam load cell with multiple beams connected in series is that the external load P applied to the large area of the load-bearing flange 9 will generate a certain eccentric load, thereby causing bending parasitic stress and reducing the measurement accuracy of the load cell.  The load-bearing flange 9 is different from the elastic element in that it is radially configured, thereby increasing the external dimensions of the elastic element on the vertical plane.  For this reason, Instron Company has designed a circular shear beam load cell without a flange, as shown in Figure 4.  Its feature is that the dimensions of the upper and lower ends of the shear strain zone are appropriately extended, which not only eliminates the flange plate and simplifies the mechanical processing technology, but also ensures the measurement performance of the load cell.